I have a 2002 Z24 with CAI and full 2 1/4" exhaust. The most restrictive part of my exhaust is the high-flow cat, so it's lacking for back-pressure. I also have the RKSport scavenging header on it, so that's even less back-pressure. I think that the open exhaust as well as intake have lead to my car wandering at idle. My car's air/fuel wanders at idle between 12 and 15 and after hard acceleration it runs really lean, as bad as 17 and 18 parts air to fuel. This is measured by a dynojet wide-band commander, so my info is not off. What can I do to get my car running right. The air/fuel ratio is very inconsistent throughout the rpm range and it feels like my car is detonating at idle sometimes, but I don't think my knock sensor is going off, because the air/fuel doesn't fall after what feels like detonation. I just replaced the spark plugs and the primary o2 sensor, the secondary o2 sensor is being handled by a casper simulator. I thought changing the o2 sensor would help, but it did not help much, if at all. I've ordered an adjustable fuel pressure regulator and I plan on getting a safc 2 later this summer, but will the afpr be enough to stop the problems at least at idle, that's where most of my problems are. Thanks for any help.


That which does not kill you makes you stronger!

Maybe you should check your your fuel system. I doubt your exhaust would cause you to run lean.

You can try replacing your fuel filter, having your fuel pressure checked, and getting your injectors serviced.