Geddy Lee

My 02 Z has been having random misfires for months that only happen when the car is in gear and you are rolling without your foot on the gas (Ex. sitting at a 4 way intersection waiting my turn to go with traffic having to stop and go constantly). I have replaced spark plugs, plug wires, pcv valve(which was broken) and had it checked multiple times by different people. Finally today I took it to a local shop. They told me that my car was having rotating misfires between ALL cylinders and also that my plugs were showing lean on one side and rich on the other side. I also find that weird because when I changed my plugs none of my plugs were running rich or lean. What causes this problem? Here is a list of my mods just in case they are needed. LS6 Tb, LS6 intake Manifold, BBK Headers, and a small tune on the computer done by East Coast Performance.

redlineshifter

Any DTC codes? I've experience random misfires due to a MAF going bad once and also from a wire breaking on an o2 sensor. They both showed codes, though.

You can check the MAF by unplugging it while it's misfiring. If the misfire stops, that's likely your culprit.

Geddy Lee

I got it fixed about a day or two after posted this, thank you for the info on the MAF though! It turned out to be a bad combination of a blew out pcv valve and bad o2 sensor. I got both of them replaced and now it runs really well. But I also found out that my mail order tune didn't tune out my rear o2's when they did it so im still throwing o2 sensor malfunctions.