# 97 Altima not passing emissions



## magicreptile (Jan 7, 2016)

Hi, I have had quite a long and confusing problem with my 1997 Nissan Altima.

I live in LA and went to get my smog test needed for registration, the emission levels were too high so it failed. The car has been running fine so I didn't think it would be a problem. I went to a mechanic and he looked at the test sheet and noticed that the levels were so close to passing and suggested driving the car for a while before taking it in to warm it up and it should pass the next time.

Eager to get it over with I took his advice and drove it an hour then back to do a retest. This second time the levels were higher and I was getting an error code (EGR?) I think its P040 code they said. So I left it with a mechanic, they gave it back and they said they fixed a hose and reset the computer and I need to drive it for 100 miles to get it to check the codes or something to know what the problem is and then they can fix it.

I drive it bring it back and 2 of 4 codes are not ready, I do this about 3 times, 500 miles and a month later and its still not ready.

So I took it to another mechanic who I've been to many times before and is more reliable because I feel like I'm getting the runaround. The current mechanic is saying the same thing, it needs more driving. He also said Nissans sometimes need a lot of miles for this code thing, he had a maxima that took about 1,500 miles for it. and until then they wouldn't know exactly what needs to be fixed. 

The thing is at this point my car registration is paid but incomplete, and I have only 2 permits that are valid for a day of driving. I'm very limited to legally drive it to put on these miles! its a really tough situation

I've read on here that a leaking gas cap could set off the code? also a canister vent control valve? 

Myself and everyone involved seems very puzzled about this. Is anyone familiar with this type of problem and has any suggestions? 

Thank you


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## rogoman (Dec 16, 2004)

Perform an ECU code readout with a scan tool and post all the fault codes here on the forum.

If you're getting a P0400 fault code, then here are some possible causes:
- EGR valve stuck closed.
- EGRC-BPT valve defective.
- Cracked vacuum hose.
- EGRC solenoid valve defective.
- EGR temperature sensor defective.
- Exhaust gas leaks.


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