P0401 '97 Lumina

ok friends....i did almost everything to get rid of the code p0401, i have replaced EGR,MAP Sensor, cleaned the egr line with carbon cleaner from Autozone, checked the inlet temperature sensor with a multimeter which is 100% in operation...

please help me to get rid of the code....is there anything i am missing?...any clues or any help is really appriciated.

Thanks.

Welcome around the forums friend.

I have a chiltons so i looked it up for ya.

The chiltons says this Word for word:


This is for the 3.8

Former DTC = 53/54/55 (dunno might help though)

Exhaust Gas Recirculation (EGR) - Flow Failure

thats a PCM code FYI

The 1996 3.1 says the same thing. EGR flow Insufficient

So its trouble with the EGR, Try getting a Brand new EGR and reset the codes. if it keeps it up i would check out the PCM and make sure its not being faulty.

Im sure Jeffco can figure it out :P

BTW jeff is a good name mine also :D

If jeffco cant figure it out, then cadgear and everyone else around here will.

First, have the code cleared to ensure that what you've tried has/has not worked, if you haven't already done so (AutoZone will do it, but so will disconnecting the battery for a few minutes). You sure you did a good job in cleaning? Most of the passages I've cleaned out produced gobs of carbon buildup, and took roughly half an hour to do.

A 0401 is essentially pretty specific on what the causes could be. Flow insufficient basically means just that; the PCM is asking for a metered amount of air and it is detecting less than what was expected. It uses the MAP to do that, and though you've replaced the MAP, you might want to check the wiring as well. Check the stovepipe from the exhaust for pressure with the engine running, haven't seen one of those clog but its always possible.

Post back if you find out something or have any further questions. More often than not a good scrubbing will take care of that code, though have it reset to ensure that is all it was.

Thanks for your help friends....

I was so sure that the job i did was 99% right...so, i took my car out for a drive....and after driving about 120 miles, the code went away by itself...

i dont believe in erasing the code with obd scanner or a battery removing....its more fun when the code resets by itself through ECM...

Thanks guys i really appriciate your help..

Thanks for your help friends....

I was so sure that the job i did was 99% right...so, i took my car out for a drive....and after driving about 120 miles, the code went away by itself...

i dont believe in erasing the code with obd scanner or a battery removing....its more fun when the code resets by itself through ECM...

Thanks guys i really appriciate your help..