cruise throttle surge

[fixkick]

[quote pid='12278' dateline='1573705965']

that's what im talking about is line 50     vacuum coming from it.
OK you do have 50,  so this car is the mono port, intake manifold, and those gaskets must not be missing seen in the drawing for this part.
gaskets both #41 and #6, or it will suck air, "leak vacuum"
ALL VACUUM LINES MUST BE ROUTED CORRECTLY FOR EGR.


valve im talking about is the egr    not sealing vacuum coming from 50. (WHEN?, IN HAND OR ON CAR AND AT IDLE)?
the surge or miss went away with the first new EGR, ( new in the BOX EGR or used? )

after about 75 miles the CEL came on with 51 code and idle would go to about 300 or 400 then recover after about 30 seconds or so to 800 other than that it ran great. none of the idle problems show till warm.  (400RPM IS COMMON WITH EGR MAIN failed and STUCK OPEN) BLOCK HOSE 23 TO STOP THAT.)
OK, but not sure what this is next below, at all, first off , the line 50 is  always  under full vaccum, with engine running, ALWAYS due to that  is the MONO port EGR injector behind the TB. (throttle body)


pulled the new egr and found vacuum from line 50 leaking through the egr valve while at idle and exhaust side closed. (this I HAVE NO IDEA what you did , exactly)
tell what you did exactly, step by step,


installed new egr and haven't driven it yet. (EGR new #2?) new in the box, (those are not cheap, )

the only non stock thing is a gutted cat do to a slide off the road landing on cat with curb.
it had been gutted for about 2 years prior to all these issues. ( I told you the EGR is 100% disabled with no CAT,  this is a fact.  )
The vacuum leak is easy to find and cure, no matter what, we can to that. but PIPE50 must have gaskets that DO NOT EVER LEAK.


At idle I have a fairly good vacuum (haven't put a gauge on it but holds a finger tight when covered) 19 inches HG vacuum is normal hot engine 800RPM (sea level )
also at idle I have fairly good Exhaust pressure put where?( again no pressure gauge ). the correct place for gauge is at bottom of MOD hose, yours is zero.
Don't need to pass smog (GOOD) so now we know for the first time there is no CAT, and EGR is now DEAD, due to that fact. so just  defeat it.  (GOLF TEE HOSE 23)
Or make blocking plate on the EGR main #5.

How do I test the egrt probe? is it a on or off switch or at different temps, different resistances (an ohm meter and hot water is the test in the FSM and my link on this line)

no it is not any kind of switch it is in fact a thermister temperature probe,  the scales for it are in the FSM and  the EGR page I linked. and is useless now that the CAT is missing.
CAT missing means (the whole thing or the BRICK INSIDE GUTTED in any way shape or form)

if the egr doesn't seal the vacuum off that comes from hose 50 what filters that air (sure it does, car parked, and at idle SURE IT DOES:
Pipe 50 is never and air pipe ever. (it's an exhaust only pipe)
. ie like the vacuum coming to valve that's turned on by the exhaust pressure to activate the egr. ( no, that vacuum line at MOD only modulates the EGR ,exhaust flows only)

thanks much I appreciate your time

your welcome,  

---

Here are some facts: about EGR...
The EGR main has spring behind the diaphragm, with no vacuum at the EGR main #5 nibble that big spring holds the valve closed, even with main held in your hand , see that?
all that matters on this car is that, that the valve closes, in hand and mounted. (but lets now learn that the MOD vavles al fail if no CAT. even 10 new MOD valves fail.

The CAT missing causes , not full backpressure to show up at Exhaust manifold port #4 (this is how the MOD valve works it measures #4 exhaust back pressure,)

The CODE 51 happens due to the MOD valve is now DEAD, CAT dead equals MOD VALVE DEAD, with MOD valve DEAD , EGRT will read cold all the time, and the DTC 51 test fail.
this is how all Sidekicks work 89 to 98,  every one G16 does this. this way. until J18 happened. engine. twin cam engine, happened.

The MOD valve is the Brains behind this EGR, system. the MOD , senses CAT back pressure and then sets vacuum flow to the MAIN-5
the faster  you go and more load on the engine (hills) the more CAT back pressures happens (yours is zero) and MORE EGR FLOW HAPPENS that way.

• Egr is not active at idle (ECU logic and VSV slave closed)
  
• EGR is not active until rear wheels turn, over 0mph, (ECU logic for this CALIF class EGR CAR) all this is normal , making EGR tests very hard parked,(the FSM covers how on jackstands)
  
• egr IS OFF LINE UNTIL ENGINE IS HOT (AS YOU CAN SEE at idle egr is offline 
  
• EGR never flows until CAT produces valid  back pressure (this is RUBE GOLDBERG system , SURE ) and works just like 95 toyota's too. (all common then)
  

The only issues, are:
EGR dead, best is to just block hose 23, so the thing can't stick open. and cause 400 RPM.
The DTC 51 fails, so you can use  3 cent resistor the fool the thing and and stop 51s. 10k ohms again covered here, fully, code 53 happens if EGRT is missing, or just unplugged.
If you must have working EGR that takes a working CAT, even one dead but has normal back-pressure, works. (UNTIL 1996 and cat tests started in OBD2, means working cat 100%)

SORRY !
I do not understand your comments on ID 50 leaks, this pipe is under full vacuum at all times running, for a fact. so not sure what you did there.? but must be kept gasket sealed. see PHOTO below for WHY !
or engiine  will go lean at idle. sucking air like that. vacuum leaks are all bad, and worse if many happen.'
No vacuum leaks from the intake valves to the MAF are good, no GOOD can happen with those leaks.  (the reason is that is un METERED AIR (MAF = meter)

The MONO port injector , injects exhaust gasses only , at no time does it send  AIR , no vacuum leaks.  that is the goal and purpose the exhaust lower combustion temps and NOX faLLS VERY LOW (SMOG GAS TOXIC)

I have this photo I made , one of the few ever made I guess.  showing the newers 95  upgrade, and better MONOPORT> EGR INJECTOR.

WITH A GOOD CAT,  THIS MONO PORT #1 BELOW IS THE # 1 FAILURE ON egR AND MAIN FAILING IS # TWO.  I HAVE THE TV BLOCKED OPEN FULLY HERE.


btw the new manifold with MONO PORT (not quad) does work on all years 92-98 we tried it, and is best, for working EGR. (less labor to keep it going in fact)

[/quote]

THIS PORT ABOVE has VACUUM full time running, IT SUCKS THERE AT 19" HG INCHES  OF VACUUM AT IDLE. BUT NO AIR LEAKS AT #1 EVER. BECAUSE EGR MAIN IS CLOSED.

I presume each new EGR you installed the EGRT was moved from the old and put on the new, and  UNSTATED .???

there are many things to fail here, vacuum leaks, here they are, Not full list just EGR list.

• Egr hose routed wrong. for sure at pipe set 14
  

[fixkick]

if curious see the new EGR system, on newer suzuki, like j18 or 1999 gen 4.

all there is , is just one electric motor, EGR,  no vacuum bull at all, just this, nice part.
legacy cars are not easy to fix. for sure EGR>

[1995 toad]

[quote pid='12278' dateline='1573705965']

that's what im talking about is line 50     vacuum coming from it.
OK you do have 50,  so this car is the mono port, intake manifold, and those gaskets must not be missing seen in the drawing for this part.
gaskets both #41 and #6, or it will suck air, "leak vacuum"
ALL VACUUM LINES MUST BE ROUTED CORRECTLY FOR EGR.


valve im talking about is the egr    not sealing vacuum coming from 50. (WHEN?, IN HAND OR ON CAR AND AT IDLE)?
the surge or miss went away with the first new EGR, ( new in the BOX EGR or used? )

after about 75 miles the CEL came on with 51 code and idle would go to about 300 or 400 then recover after about 30 seconds or so to 800 other than that it ran great. none of the idle problems show till warm.  (400RPM IS COMMON WITH EGR MAIN failed and STUCK OPEN) BLOCK HOSE 23 TO STOP THAT.)
OK, but not sure what this is next below, at all, first off , the line 50 is  always  under full vaccum, with engine running, ALWAYS due to that  is the MONO port EGR injector behind the TB. (throttle body)


pulled the new egr and found vacuum from line 50 leaking through the egr valve while at idle and exhaust side closed. (this I HAVE NO IDEA what you did , exactly)
tell what you did exactly, step by step,


installed new egr and haven't driven it yet. (EGR new #2?) new in the box, (those are not cheap, )

the only non stock thing is a gutted cat do to a slide off the road landing on cat with curb.
it had been gutted for about 2 years prior to all these issues. ( I told you the EGR is 100% disabled with no CAT,  this is a fact.  )
The vacuum leak is easy to find and cure, no matter what, we can to that. but PIPE50 must have gaskets that DO NOT EVER LEAK.


At idle I have a fairly good vacuum (haven't put a gauge on it but holds a finger tight when covered) 19 inches HG vacuum is normal hot engine 800RPM (sea level )
also at idle I have fairly good Exhaust pressure put where?( again no pressure gauge ). the correct place for gauge is at bottom of MOD hose, yours is zero.
Don't need to pass smog (GOOD) so now we know for the first time there is no CAT, and EGR is now DEAD, due to that fact. so just  defeat it.  (GOLF TEE HOSE 23)
Or make blocking plate on the EGR main #5.

How do I test the egrt probe? is it a on or off switch or at different temps, different resistances (an ohm meter and hot water is the test in the FSM and my link on this line)

no it is not any kind of switch it is in fact a thermister temperature probe,  the scales for it are in the FSM and  the EGR page I linked. and is useless now that the CAT is missing.
CAT missing means (the whole thing or the BRICK INSIDE GUTTED in any way shape or form)

if the egr doesn't seal the vacuum off that comes from hose 50 what filters that air (sure it does, car parked, and at idle SURE IT DOES:
Pipe 50 is never and air pipe ever. (it's an exhaust only pipe)
. ie like the vacuum coming to valve that's turned on by the exhaust pressure to activate the egr. ( no, that vacuum line at MOD only modulates the EGR ,exhaust flows only)

thanks much I appreciate your time

your welcome,  

---

Here are some facts: about EGR...
The EGR main has spring behind the diaphragm, with no vacuum at the EGR main #5 nibble that big spring holds the valve closed, even with main held in your hand , see that?
all that matters on this car is that, that the valve closes, in hand and mounted. (but lets now learn that the MOD vavles al fail if no CAT. even 10 new MOD valves fail.

The CAT missing causes , not full backpressure to show up at Exhaust manifold port #4 (this is how the MOD valve works it measures #4 exhaust back pressure,)

The CODE 51 happens due to the MOD valve is now DEAD, CAT dead equals MOD VALVE DEAD, with MOD valve DEAD , EGRT will read cold all the time, and the DTC 51 test fail.
this is how all Sidekicks work 89 to 98,  every one G16 does this. this way. until J18 happened. engine. twin cam engine, happened.

The MOD valve is the Brains behind this EGR, system. the MOD , senses CAT back pressure and then sets vacuum flow to the MAIN-5
the faster  you go and more load on the engine (hills) the more CAT back pressures happens (yours is zero) and MORE EGR FLOW HAPPENS that way.

• Egr is not active at idle (ECU logic and VSV slave closed)
  
• EGR is not active until rear wheels turn, over 0mph, (ECU logic for this CALIF class EGR CAR) all this is normal , making EGR tests very hard parked,(the FSM covers how on jackstands)
  
• egr IS OFF LINE UNTIL ENGINE IS HOT (AS YOU CAN SEE at idle egr is offline 
  
• EGR never flows until CAT produces valid  back pressure (this is RUBE GOLDBERG system , SURE ) and works just like 95 toyota's too. (all common then)
  

The only issues, are:
EGR dead, best is to just block hose 23, so the thing can't stick open. and cause 400 RPM.
The DTC 51 fails, so you can use  3 cent resistor the fool the thing and and stop 51s. 10k ohms again covered here, fully, code 53 happens if EGRT is missing, or just unplugged.
If you must have working EGR that takes a working CAT, even one dead but has normal back-pressure, works. (UNTIL 1996 and cat tests started in OBD2, means working cat 100%)

SORRY !
I do not understand your comments on ID 50 leaks, this pipe is under full vacuum at all times running, for a fact. so not sure what you did there.? but must be kept gasket sealed. see PHOTO below for WHY !
or engiine  will go lean at idle. sucking air like that. vacuum leaks are all bad, and worse if many happen.'
No vacuum leaks from the intake valves to the MAF are good, no GOOD can happen with those leaks.  (the reason is that is un METERED AIR (MAF = meter)

The MONO port injector , injects exhaust gasses only , at no time does it send  AIR , no vacuum leaks.  that is the goal and purpose the exhaust lower combustion temps and NOX faLLS VERY LOW (SMOG GAS TOXIC)

I have this photo I made , one of the few ever made I guess.  showing the newers 95  upgrade, and better MONOPORT> EGR INJECTOR.

WITH A GOOD CAT,  THIS MONO PORT #1 BELOW IS THE # 1 FAILURE ON egR AND MAIN FAILING IS # TWO.  I HAVE THE TV BLOCKED OPEN FULLY HERE.


btw the new manifold with MONO PORT (not quad) does work on all years 92-98 we tried it, and is best, for working EGR. (less labor to keep it going in fact)

THIS PORT ABOVE has VACUUM full time running, IT SUCKS THERE AT 19" HG INCHES  OF VACUUM AT IDLE. BUT NO AIR LEAKS AT #1 EVER. BECAUSE EGR MAIN IS CLOSED.

I presume each new EGR you installed the EGRT was moved from the old and put on the new, and  UNSTATED .???

there are many things to fail here, vacuum leaks, here they are, Not full list just EGR list.

• Egr hose routed wrong. for sure at pipe set 14
  

[/quote]

yes I have line 50 and both gaskets are new and tight
All lines are there and look to be properly located.

it is in my hand when I am putting vacuum to the port where the line 50 would attach. and it will not hold a vacuum.
the valve was new in the box from oreilys auto. the second one was a warranty replacement. first cost $150 ish.
I will try the blocking of the 23 hose. I did put pressure on the exhaust side of the egr and got no leakage.

So with no cat the egr will always show a code 51 because there is not enough pressure to operate the mod valve? At Idle I have pressure that I can feel at the egr mounting flange where it comes out of the block. how much pressure is needed to operate the mod valve. 
not to say the egr was operating but it didn't throw any codes in the about year and a half that the cat had been gutted. 

so putting a plate over the egr mounting boss should keep line 50 from leaking vacuum. and plug the  exhaust port if I threaded the probe into that plate would that keep the egr code from appearing or is the resistor the only way to trick that?

I still need to drive this new egr and see if the code comes back and the Idle is still affected.

I just find it strange that the old egr was working or not throwing codes to be more specific. with the cat gutted.

 Ill try to figure out how to add pics in here and show you better what Im not very good at explaining... more of a mechanical guy than a tech guy.

thanks again.

[fixkick]

(answering INLINE)
yes I have line 50 and both gaskets are new and tight
All lines are there and look to be properly located.

it is in my hand when I am putting vacuum to the port where the line 50 would attach. and it will not hold a vacuum. ( holding means what, a hand pump vacuum tooL?)
I can still not imagine what you are doing above.  hard line 50 has 2 ends,
Here is MAIN EGR mount, and the tube fitted up,  are you saying engine turned off key off, the EGR tube removed, you can not  pull a  vacuum with a hand too at the tube 50 port.?
or are you saying the TUBE 50 leaks air (always normal thata)   tell what test you do , now and if engine running or not, and level of disassembly for test.
The "S"bend Bark port, on the left goes to the left port (egr main IN) the out port goes to TUBE 50 only.  No body has path drawing inside  this intake man. Let me explain that.
what if you tired to test port 50 with the EGR removed, would the mouting holes like , GEE I DO NOT KNOW. (no drawing exists for this)
Test the EGR in hand only main in hand,  then test the EGR with EGR main fitted to the intake with gasket,
The EGR main mounted, will not bark at the out port engine running, if yes, then the EGR is good, the push in the magic EGR ring test, now it barks to port 50, end test EGR mail.



the year before this was QUAD port EGR injectors inside the intake MANifold and extremely hard to cure carbon clogs. this genius way means only pipe 50 clogs or up top, vastly more easy to service.  I call the GEN2 mono port EGR.
EGR can fail many ways,  (vacuum fails , exhaust fails) and EGR dead, , EGR WEAK and EGR stuck on (400rpm syndrom) and EGR works RANDOMLY.  yes, EGR is a pain.(can be)
that is why my EGR tests, show how to find most of those in fast simple tests.

The ECU has many modes, and the cold engine runs in the cold mode,  not to be confused with hot engine mode.  (EGR ONLY RUNS IN HOT MODE)
The OLD mode idle is controlled by that funny thing (IAC) below the TB,  it is 100% thermal mechanical part, not electrics.
then when hot the ECU and ISC (electric) takes over idle speeds, and loves to get dirty inside (ISC) and stick and fails to control hot idle at 800rpm (AC OFF)
400rpm hot, smacks of EGR main stuck open. (as they love to do but newer a new one)

I do not at al under stand your port pipe 50vacuum leak test at all , I what you did to do that, how, and with what tools (hand pump or vacuum gauge ) no idea at all  this. but seems to me done wrong, I test the EGR on the car mounted so there are no leaks, 

the valve was new in the box from o-Reilly auto. the second one was a warranty replacement. first cost $150 ish.
I will try the blocking of the 23 hose. '
I did put pressure on the exhaust side of the egr  (MAIN I presume) and got no leakage. ( EGR main in hand ?) GOod the valve closes, and expected, it is after all new EGR main.

So with no cat the egr will always show a code 51 because there is not enough pressure to operate the mod valve? (that is TRUE, and can be proven my EGR test page and the factory FSM book shows how to do that test and prove that fact. for sure.)

At Idle I have pressure that I can feel at the egr mounting flange where it comes out of the block. (I do not understand this line here, is this EGR removed? main?) IDK what you did.

how much pressure is needed to operate the mod valve.  0 to 2 PSI,  the full #4 exhaust port pressure is at FORCE HERE, that is how this works via the head tunnel EGR port.
not to say the egr was operating but it didn't throw any codes in the about year and a half that the cat had been gutted. ( THE egr TESTS ARE TRICKY HOW AND WHEN DONE)
THE ecu HAS PRESCONDITIONS FOR THE TEST, (HOT ENGINE, MOVING, AND GOING FAST, AND ENGINE LOAD MUST BE WHERE IT WANTS AND BAM CODE 51 TEST IS RUN.
IT ONLY LOOKS FOR DEAD EGRT AND HOT UNDER LOAD AND AT NO OTHER TIME.  OBD1 testing is covered in the FSM.



so putting a plate over the egr mounting boss should keep line 50 from leaking vacuum. ( keep in mind it took many posts until i saw you had pipe 50, ok:?) no photo of your
NO not this car, takes a tube 50 must Be blacked at the back side of upper tube 50 removed.
in other countries, Suzuki sells  a kit for this and sells cars like it, like Sold in SOUTH PACifica ISLAND or with VIN plate marked JDM version (I call them slicks, devoid of smog parts)
The car with pipe 50 needs 2 plates or just one hind the TB the port 50 mount at the top behind the main Plenum.

and plug the  exhaust port if I threaded the probe into that plate would that keep the egr code from appearing or is the resistor the only way to trick that?
The resistor trick works  EGRT in place (so it cant leak)  and then put said resistor across the 2 matching harness pins.  then the ECU thinks the EGRT is present. and is not.

I still need to drive this new egr and see if the code comes back and the Idle is still affected.

I just find it strange that the old egr was working or not throwing codes to be more specific. with the cat gutted.
1995.5 car is a one only car and this EGR system was faulty, the EGRT sensor proved be illegal in 1996, OBD2, because of many reasons but I can do 4.
1: it only tests for hot under load. (this is a bad idea. (can can be fooled easy. ) as the resistor proves .
2: the EGRT loves to pack in carbon and fail easy, (false reports, suck)
3: The EGR system was not tested for NON CLOSURE.  1996 the cut fuel test , was added, OBD2 EGR test B.
4: The EGRT does not really prove EGR is working at all ,  only that it gets hot, and never proves NOX reduction is working.

The test is lame and unreliable, kinda like trusting Carrier Pegeons for reliable communications... fail.  the next year ended this CALIF 95.5 EGR horror. 

one more reason for cat break up, the MUFFLER,  ends up with all  those chucks of CAT guts bricks landing the the muffler and blocking up its baffers causes back pressure.
or car this old has some wrong  muffler that is very restrictive, and making EGR work (amazing ,no, 2 wrongs make a right) This happens in EFI system. 2 sensor sensor failing can.

RECAP; and back on topic
new EGR (or pipe 50 blocked some way) plug the hose 23, with at golf tee, (easy way) screws work too but damage the rubber hoses.
now the EGR system is 100 % dead.
or just make plate for upper pipe 50, mount, block the plenum 50 port, with a plate , but this is more work. far far beyond hose 23 plug up for just a simple test.

All you are doing is proving EGR causes the idle problems or surge  or NOT.  (there are huge lists of reasons for that, not just EGR, EGR is only one cause)


now hose 23 and how it works for testing EGR, covered on my EGR pages, endless near. (stall tests. and bark tests and LIVE TEST !!!! ,etc)
PIPE #50 mount (dont do this) with welch plug pulled. clean the path from both ends, do not pull this plug


my new 96 exh manifold , and my trick to show, see here it is. clear as day.  this is the CAT back pressure SENSING PORT !


this is the bark tube path, to head tunnel to intake man, this is how EGR  ENGINE LOAD is measured using CAT back pressure, (large)  that is how this works, for sure.
On modern cars load is just MATH inside the ECU, (RPM/vacuum/MAF flows,and Throttle angles will get you ENGINE LOAD, as all 96+ cars do )

with no CAT present , Exhaust back pressure are NOT KNOW by anyone on earth, 1000s of mufflers sold and some glass packs and even no mufflers at all used offroad. endless.
UNDEFINED IS THE WORD. here.
the point of fact is the CAT must be present for EGR to work , the other fact is the EGR tests are poor, and lie to you, even with bad EGR shows all is happy.(tests)
the stall test is easy,  and not get burned fingers., see engine stall or on very strong engines goes to 400PRM.
we grab the trusty shop hand vacuum pump gauge tool (as seen and harbor freight for $30, or the old mityVac tool ™
then with hose 23 in hand pull a vacuum and see the diaphragm move in (a mirror needed on any 16v to see that) and then engine stalls, as my video shows on my EGR pages.
we also hand press the ring on the rear of the egr cold engine, with finger to see valve open and close,  all on car, and if those 3 tests pass. EFR main IS OK.(and leakdown on the diaphragm tests, as we always do on all diaphragms of any kind),, they do crack, and see of the valve also likes to stick, but gee yours is new.
a video of my EGR page, shows what it does,  (and engine with full compression spec, or not up on the rocky mountains will not stall ,just go to 400rpm or so)

seen here  https://www.youtube.com/watch?v=UPO7B7yH43w

The live test is covered in the FSM.seen here
here is the EGR (but uses po400 errors , in 1996 uP but works just the same, with no EGRT, uses EGR MAP.(fancy)

https://www.acksfaq.com/HTML/pdfs/96-FSM-v2-6e3-c7.pdf

chapter v2, 6e-3-c7 shows this, then the FSM flat fails to telly make sure the CAT is not missing or gutted,  (30 years later, gee, they are)


that is it, EGR testing is easy and vacuum tests are in the FSM./
the only hard test is the LIVE test ,, with car on 4 jack stands, very very carefully this test is very dangerous, with rear wheels going say 1mph. (not zero mph)
the ECU needs hot engine, and rear wheels spinning, and then looks at the VSS (veh, speed sensor) and if it clicks (over 0mph) EGR THEN OPENS, main.
That live test  is not easy, well is,  but dangerous.  best is on huge veh. lift safe and sound.

The hard EGR problems classic are those bark paths blocked 100 % or worst, 90% (carbon can pack any what it wants)
then CAT missing (2nd) I wonder how many of these old near 3 decade cars have a working cat, outside smog test zone, , ZERO?
no cat lasts 30 years. some even have welded on wrong CATS off 3 liter donor car, and fail.   only 2.Liter or less work here.
yours is 25 years old,  and that is OLD. (means expect anything, good ,bad , ugly, wrong or missing)

for sure good luck to you ,!!!

[fixkick]

NO CAT  , gutted cat, and CAT's guts blow out the tail pipe end or lost inside some unknown muffler to the rear, mean.
Back pressures normal are gone and now indeterminate.
YES CAT the back-pressures are 100% known and the brain inside the MOD valve, is modeled after this fact, 2PSI max we think, as measured at the O2 bung port.
We know this because 1: we do the pressure  readings to find melted CAT and then see it 2 times, once bad, then good. 2psi WOT.
We know this because FSM says  so and we find missing cat guts all the time and the EGR LIVE TEST FAILS and we can replace the MOD vaLVE 10 times an not cure the MOD valves wrong outputs, doing the tests the correct way. we learn that.


see this EGR page out of 96fsm and then annotated for older.  this answers all your questions as to when and how.

http://ge.tt/6gvplbp2/v/32

[fixkick]

now the EGR test weakness, covered .  (all kicks with this sensor same deal)
the EGRT test is really really dumb (cured  in 96)

the test is but one 1 test per driving cycle (means cold started then hot engine)
What if the EGR valve leaked, (oops no leak tests done on this car) so the hot exhaust gasses leak to pipe 50 and the silly dumb ECU logic sees the hot EGRT and thinks it is all GOOD.
that is why EPA banned the bugger. IT IS NO GOOD this and the ECU firmware test EGR IS NO GOOD. (call it a half baked plan)
The correct test is to make sure it is EGR cold readings on a hot engine shows, that the sensor is cool when EGR is not active, then do the hot test next, (oops)
I might add, the ECU does do DTC53 telling you the EGRT  sensor is missing, unplugged, or dead open circuit in side, but is wrong is there is no EGR LEAK TEST DONE THIS IS pure PAIN on this  car.
this is why the 10k ohm resistor trick works it fools the silly thing into a happy state. (1 test, hot engine and happy)  
my answers are not to cheat or make more smog (never)_
my answers are to solve complex problems with EGR here, and it is complex, a RUBE GOLDBERG mess.... https://media.giphy.com/media/mYqaRkXyoGbcY/giphy.gif

ON MORE bad thing. the EGR in some countries, do not do code 51 tests, for sure JDM cars, and even cars in Canada, yah (or EU< vitara is same car called Vitara)
the CALIF car for sure does this test, and is the worst state country /state rules.  car CALIF.
the CALIF car may go to LIMPHOME mode ( failsafe) and go super rich AFR (air/fuel/ratio),  and car gets 15mpg not 28mpg.  this only happens on some cars in usa. fed/calf.and is not documented
these cars go to limphome when sensor fail. (go dead = fail) the worst cars are 95 and older. 96 up , does far better (vastly so) The 96 is smarter, it tries not to burn up a good CAT, in fact. (amazing no?)
95 and older love to burn up a good CAT, this is a fact. some even glow the CAT RED HOT, (in the dark seen)

the EGR on this car uses Exhaust pressure and vacuum circuits and ECU logic to run the EGR normally and test the EGR for 1 simple(or missing) failures. (barbaric it is)
I cover CAT backpressure here extensively,  check it out. (i even quote real Suzuki manual data)


if MPG is ok,, then failsafe is not happening , a very good thing.