The CEL light on my 97 came on, so I took it to autozone to get the codes checked. Got 2 codes:

P0307 - number 7 cylinder misfire detected

Po401 - EGR system fault. The ECM has detected too little flow on the RGR system.

I used pmohr's lookup to get more info and neither code is in the look-up.

The car seems to run fine, no missing, good power.

Some advice please.

 

You have a V6, no #7 cylinder, maybe thats why it's misfiring.

 

My thoughts precisely, but I checked under the seats and in the trunk anyway

Any other ideas?

 

I think bad gas can also cause a misfire code. If i see a code like this for the first time, I reset the ECU and see if it comes back.

 

it could but i would also expect to see a ks code. if you say the car is running fine i would do as nick suggested.

 

I had a lot of problems wrapping my head around a #7 cylinder mis-fire code so I took the car to another auto parts store that we have here called O'Reilly's. Their tester came back with P0325 knock sensor and P1447 Evap purge flow monitoring. This is more believable. I reset my ECU and drove the car for about 5 minutes and the light stayed off. All I can do is wait and see.

 

How new are your o2 Sensors. Sometimes cleaning those off can help with EGR. THe ECU will see better o2 numbers and not think the EGR is malfunctioning. Its a low budget trick that may work especially if the o2 sensors are old.

 

The car is stock, no mods with almost 130K miles. The O2 sensors are the originals as is the whole exhaust system. My wife is out driving doing job search stuff so when she gets back, I'll find out if the CEL light came on again and then start doing things. Even if the light is off, I suspect that it will come on again sooner or later because of the age of the car.

edit for grammar