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Never ending problem with check engine light on '97 Nissan Altima

My '97 Nissan Altima has its check engine light on. I went through 2 mechanics to get this fixed. The first one replaced a bunch of things - the solenoid, transducer, cleared the passages. The light came back on. Then I took it to the second mechanic because I wouldnt qualify for a waiver unless I went with a MA certified emissions shop. Those guys replaced the EGR temperature sensor and cleared the passages there. That didnt fix the problem. The light is back on.

The car runs perfectly fine and gives me 30 mpg on the highway - almost like when it was new. But the light comes on consistently after repairs and the monitors have run.

The mechanic tells me that the only other options are the following:

a. Replace the EGR valve.

b. Open up the intake manifold and clear the passages there.



I have already spend over $1000 on this problem and dont wish to spend more. But I want to see if there is any way the computer can be reflashed. Given that the car runs so well, I am thinking that reflashing is the best option - if it is available. When I took it to the dealership they told me they dont have a reflash for the EGR system.

I cant get MA to give me an inspection sticker because of this problem.

Any advise, guidance will be appreciated?

Ask the mechanics what the stored computer fault codes are. Someone here may be able to help you if you let us know what the mechanics know.

The code has always been the same. It is the P044 code.

You can’t spoof the computer but you CAN reset the CEL just before you have your next emissions test…Just disconnect the battery for 30 seconds. On newer vehicles, this does not work because the computer will rat you out to the testing machine, but it’s worth a try…

Next step is to ask your State Rep if he can prove emissions testing reduces air pollution. Also, with $1000 spent (wasted) don’t you qualify for a waiver??

The plumbing to and from the EGR valve would have been the first thing I checked, before replacing any parts. Get the intake manifold passages checked for clogging. My neighbor just went through the same thing: lazy mechanics spent a lot of time and money replacing parts before they checked and cleaned out the EGR passages.

They have cleaned out the plumbing to the EGR valve - as far as I have been told. But to check and clean the intake manifold - this mechanic says it will cost close to $1000 to do. He explained it to me and even showed me what needs to be done and where the plumbing is. Seemed pretty laborious to me. Are we talking about 2 different things?
Caddyman,
Thanks for your response. I dont qualify for a waiver yet because I spent the first $800 or so with a mechanic that was not a certified emissions repair guy. I never thought I will need a waiver so I took it to the mechanic I always used.

“Are we talking about 2 different things?”

No, we’re talking about the same thing. I guess taking the intake manifold off a v6 is a bigger deal than a 4 cyl. From a DIY perspective it’s cheaper to test & clean things than replace parts. Maybe check around for a better price.