Hey whats up guys I've got some concerns about how my car is running right now. Its a 2004 evo 8 and a few months ago the motor blew. I sent the motor out to buschur and the cars been back on the road for a few months now. It's got a 2.3 buschur motor gsc s2 cams and basic bolt ons, still on the stock turbo and was tuned at ivey. Now onto the problems... When I first start the car from cold it idles fine around 14.5-15 afr. However after driving for a little then coming to a stop the afr at idle goes crazy. It goes all the way down to 12-12.5 and then jumps back to 15 then back down to 12 etc. It doesn't do this all the time though sometimes its completely normal idle. I also have a check engine code that goes on and off for the o2 sensor I think it was p0134. Took the car to a shop and had them replace the sensor but the afr didn't change at all and the check engine light still comes on sometimes. It's usually on for a few days then off for a few days. I'm pretty confused right now as to what's going on, if you guys could give me any input it would be greatly appreciated.

 

Did you check your vacuum lines?

 

Yep, couldn't find anything leaking

 

If no boost leaks found then best thing to do is consult your tuner as it maybe in fault in your tune. As for the 02 sensor I'd say do a continuity check there maybe a faulty wire somewhere.

 

Sensor is in the proper location? Just grasping at straws here.

 

I was reading in another thread where someone was having the same problem that he found out that the cam angle sensor was installed incorrectly and that was what was causing his rich idle. Does anyone know how I could check to see if it is installed right?

 

If it were, you should get a CEL. Not sure that it would cause a rich condition.