YOur car is 1.6L 16v 1996 Tracker.
and photos too.
provided by nice folks here.
this is with the freeze plug out. (just for illistration)
clean the whole path ,end to end,
do the stall test. if it fails. then it is not clean. (89-98 1.6L , not on 1.8L it's diff)
if car has mod valve and all the other bits, and the path is clean and it still fails, then
you must test each part.
if that passes , then rarely one must do the live test.
you didnt say how many miles your are driving to get P0400 ,/
10k, or 50k
EGRs are all high maintenance.
on a 96 , it might not even be the EGR !!!
there are 2 tests.
if you rent a full scan tool you can pull down the freeze frame.
this shows you whitch of the 2 tests are failing !
it also shows you what the numbers were.
test 1 is a above 28mph cruise test.
test 2 is a DeCeleration test.
if engine has air leaks, the EGR may fail.
its like the DR saying, you have high blood pressure.
you lost your job and the 401k has tanked. sucks huh
but that ,is a false positive. (good heart, bad economy) LOL.
are you only failing P0400.? any other codes setting? throwing?
also the real scan tool can show pending fails , that erase before they set. (marginal fails)
low vacuum , exhaust leaks, sticking valves. bad MAF, TPS or all on the list of bad things that can cause a EGR DTC to throw.
in fact that is the first line in the book. Make sure the sensors are working. maf,tps,etc.
What I would do is make sure the EGR is not leaking and stuck open (main valve)
if that is ok.
then I would check all sensors first for correct data
then air leaks and exhaust cracks.
many here look under exh. shields and just cry. CRACKS>>> everywhere......
"I know when it's cold the engine is a little loud till it warms up."
dont get me wrong, if engine is sound and EFI is sound.
the P0400 is telling the truth.
what is total mileage on car.
have you replaced the PCV valve ever. it might be stuck open or wrong size.?
If engine has lots of blowby, it will clog EGR faster.
I would suspect bad gas last.