Poor MPG

[gorkyb]

Hi all, I have noticed MPG went down on my Tracker. I calculated it went down to 20.5 MPG in the last fill up.

Here are some things I know I have to fix. I'm just wondering which one is the poor MPG directly related to?

- CEL is on for code P0420. I think this is from an old exhaust leak around the cat. Downstream oxygen sensor is fairly new and last I checked the cat visually it wasn't clogged. I have one of those inspection cameras I want to use to see if the cat is not melted. I think I can insert the camera either from the back where the pipe meets the muffler or the more labor intensive method of unbolting the down-pipe from the bottom of the exhaust manifold and insert the camera there.

- CEL is on for code P0400. This one recently came on, I knew I had the P0420 but not this one. I will clean EGR and passages the best I can without removing intake manifold.

- Speedometer is slow. Every time I come to a complete stop and start going again it takes about 3 seconds to start working, once it starts it works fine. This one is new for me, I've been reading about this and it seems it may be the metal cup broken behind the cluster?

There are no other symptoms, car starts right up, it does not miss a beat. No bogging or anything like that. I do not want to spend too much on fixing this but I want to get it running right again. I'm moving abroad and will end up selling the Tracker in the next couple of months anyway.

[fixkick]

420 means the cat is dead or lazy, (or the AFR is so far off , the cat is overpowered)
the 96+ usually suspends the 420monitor totally if things are so bad,but it might be marginal problems.
nice camera, i have one too, and is a labor saver for sure,
400 is one of 2 EGR tests failing, (on this car it has an EGR map sensor, that proves , pass /fail here) "its not flowing" does the stall test pass? by hand or better
using the hand vacuum tool at EGR main?
speedo, the needle side is , mag coupled so if the grease there gets cold, it will balk.
the magnet turns and if the odometer advances, the cable and mag are turning ok but if at the same time the speedo is dead, it's the needle side failing, (stuck) and only a nuisance.
the VSS is not failing or you'd get VSS DTC errors. and that can effect mpg. but it's not this case here.
http://www.fixkick.com/specs/orig-sales-sticker.jpg
20 mph is normal for slow driving in snow. lower left corner is (true range), seen many do 24 , under adverse conditions.

the cat is easy to test, with any vacuum tool, gun engine see vacuum drop FAST and low inches, then release throttle and see fast sharp increase to 26inches HG, a good cat. (at melted cat will make vacuum lazy , horribly)
by good , i mean not melted, or any exhaust restrictions. (proves engine can pump air)

420 dont cause mpg changes (just cat), it's only lazy cat.(in most cases)
most folks ignore 420s. for sure on very old cars. (but a new one can be welded in cheap, non OEM)

SCAN tool:?
ECT at 180F?
closed loop at idle
LTFT near -5-8% (minus)
closed look ok at 40mph (about) light cruise, flat ground, steady easy foot.
yes, then all is mostly well.

good luck and we will miss you !

[gorkyb]

I'll take a look at the scans. Thanks for the pointers. Don't be too quick to miss me, it's in my plans to get me a 2009 or newer Chevrolet Vitara 3 doors in South America. I'm just trying to figure out what I'll need to be able to communicate with the ECU, I know for a fact the generic OBD2 scanners do not connect to the Ecuadorean made Sidekick.

[fixkick]

gas engines. not diesel.
dont be sure, look first.
look at car, under right dash, see the D- shell?, connector female?, what pins are populated tells me what it is .
populated pins.?
pin 7 is first 1996 cars, usage. by suzuki. (and many others) in 1996 there were 3 scan tools sold that dont work on fords, chevy or Chrysler. later that merged.
next years the went to pins 2 and 10 for comms.

pin 4 and 5 are ground, a must
pin 16 power a must. 12vdc all time keyon. (dome fuse on most.)
see last table here called compliance
http://www.fixkick.com/CEL/DLC/DiagJump.html

then later they added CAN-BUS, 2004
pins 6 and 14 (2004) or as the maker wants world wide, or at all.

see table here, it shows all PCM with a standard , all standards there

http://en.wikipedia.org/wiki/On-board_diagnostics


pin 9 is suzuki ABS comms. 1996-1998

generic, scanners, not all tools scan all things,
for sure older tools are near useless today,
every try a Innova 3160, see if it works??
mine does 1996 to now , on all cars. USA.
OBD2 is a usa spec, and invention
EOBD is EU (ISO)
JOBD is japan only.

others are OBD1, non standard, up to 2006. some countries adopted in 2001.
ive no idea at all what is in an Ecuadorean Ssuzuki,
but the FSM will tell that.? get one with car?

austraila went oBD2 in 2006
but not sure in Ecuador.
i think they may be still suzuki secret OBD1, (zero protocol docs)
id still look for the 16pin
and pin populations. hope for it.