welcome,Jorgi !!!
first thing to be said, is that the ECU might run the EGR tests (called monitors) and actually should not, do that, if other things are wrong,
in fact if the engine vacuum is bouncing , the EGR map sensor will see that and can fail the EGR test even with a fully good EGR SYSTEM.
the ECU is not too smart here,
best is to do the tests first and not throw $300 in parts. (IMO) in all cases.... but a new EGR is good to have, they love to stick this old.
REDUX. answering ONLY for 1996 USA CARS with OBD2 , as clearly seen P0400 means, its USA car, even if bought in Canada, it has USA market sticker under hood. to get that code, (in 1998 canada copied our system OBD2)
really all this is covered in my gen3 page, read that?
just one page linked to all causes, and all tests,, I do cover every single way to get 400s, how it works and prove all myths wrong, USA invented ODB2 so , if you read books not 1996 or from other countries all facts you read are lies. that is a fact.
505 is bad idle , in most cases its due to bad EGR. (or misfire grossly , or just like EGR does, bad)
If fact the ECU should not run EGR tests if 505 sets, and others.... but seems yours does.
400 means test A or B EGR test , OBD2 rules
we connect a scan tool (all work here every otc brand) and see the Freeze frame data. to see if mode A or B failed, called MONITOR A or B
in English that means cruise fails or deceleration test fails for EGR.
most times it dont matter but is nice to know mode. failing, for ration diagnosis.
so do the stall test first
my page tells you exactly what to do, if it fails, we fix THAT First.
my very strong engine (new) runs at 400 rpm stall tested, and shakes like a wet dog, due to gross misfire, because EGR open at idle is an illegal mode, but is test one,here
my choice page (years, and countries, if you know generation class)
http://www.fixkick.com/EGR-choice.html
then yours, called GEN 3 (usa refr, point of views only)
http://www.fixkick.com/EGR-Gen3.html
see this page, see stall test, do that.
if the test is dead, the EXHAUST path is failing all in 5min work, 2/3rd of the work is eliminated, (if lucky my 96 had 2 fail points, stall failed and when corrected the VSV was dead, dang, life is hard)
on a cold engine does the egr diaphram flex by inserting and index finger there. this is really first 1st tests. see?
first thing to be said, is that the ECU might run the EGR tests (called monitors) and actually should not, do that, if other things are wrong,
in fact if the engine vacuum is bouncing , the EGR map sensor will see that and can fail the EGR test even with a fully good EGR SYSTEM.
the ECU is not too smart here,
best is to do the tests first and not throw $300 in parts. (IMO) in all cases.... but a new EGR is good to have, they love to stick this old.
REDUX. answering ONLY for 1996 USA CARS with OBD2 , as clearly seen P0400 means, its USA car, even if bought in Canada, it has USA market sticker under hood. to get that code, (in 1998 canada copied our system OBD2)
really all this is covered in my gen3 page, read that?
just one page linked to all causes, and all tests,, I do cover every single way to get 400s, how it works and prove all myths wrong, USA invented ODB2 so , if you read books not 1996 or from other countries all facts you read are lies. that is a fact.
505 is bad idle , in most cases its due to bad EGR. (or misfire grossly , or just like EGR does, bad)
If fact the ECU should not run EGR tests if 505 sets, and others.... but seems yours does.
400 means test A or B EGR test , OBD2 rules
we connect a scan tool (all work here every otc brand) and see the Freeze frame data. to see if mode A or B failed, called MONITOR A or B
in English that means cruise fails or deceleration test fails for EGR.
most times it dont matter but is nice to know mode. failing, for ration diagnosis.
so do the stall test first
my page tells you exactly what to do, if it fails, we fix THAT First.
my very strong engine (new) runs at 400 rpm stall tested, and shakes like a wet dog, due to gross misfire, because EGR open at idle is an illegal mode, but is test one,here
my choice page (years, and countries, if you know generation class)
http://www.fixkick.com/EGR-choice.html
then yours, called GEN 3 (usa refr, point of views only)
http://www.fixkick.com/EGR-Gen3.html
see this page, see stall test, do that.
if the test is dead, the EXHAUST path is failing all in 5min work, 2/3rd of the work is eliminated, (if lucky my 96 had 2 fail points, stall failed and when corrected the VSV was dead, dang, life is hard)
on a cold engine does the egr diaphram flex by inserting and index finger there. this is really first 1st tests. see?
http://www.fixkick.com