Rich issues
Thread Starter
Staging Lane
Joined: May 2018
Posts: 60
Likes: 2
Rich issues Ok so I have a 02 z28 with tea ported heads, 233/239 tsp cam, fast 92 intake, headers, and a 4000 stall. The issue I’m having is when I’m tuning the car runs 12.5-13.0 afr and runs great as soon as it’s flashed then after a bit of driving it gets pig rich and ends up at 9.0 afr. What could cause this? Maybe 02 sensor?
TECH Fanatic
Joined: Oct 2014
Posts: 1,220
Likes: 179
From: Virginia
Ok so I have a 02 z28 with tea ported heads, 233/239 tsp cam, fast 92 intake, headers, and a 4000 stall. The issue I’m having is when I’m tuning the car runs 12.5-13.0 afr and runs great as soon as it’s flashed then after a bit of driving it gets pig rich and ends up at 9.0 afr. What could cause this? Maybe 02 sensor?
TECH Fanatic
Joined: Oct 2014
Posts: 1,220
Likes: 179
From: Virginia
Are you going through the entire process? As in, tune the idle (to good enough at least), then VE, then MAF, then spark (making needed changes if knock occurs out of this order obviously). If you start at the VE, then you should be able to get the MAF in pretty quick. This really just sounds like fuel trims coupled with a bad VE or MAF table. Are your fuel trims on?
