One Bank Running Rich

[Boostd1]

Before I get flamed, I'm still learning LS1 tuning and diagnosing problems with the LS1 (3800 V6 Tuning Veteran here, trying something new) so try not to poke too much fun.

My buddies WS6 was running like total crap. We pulled out all the spark plugs and Bank 1 (Drivers side?) all looked ok, but the other side's spark plugs were just very very black. Driving around town, sometimes the wideband readings are totally normal, and sometimes at cruise it goes to < 10.0 AFR's and it sounds like a pretty hectic misfire out the exhaust.

I know (at least think) that each bank of the motor is ran separately, so what should I be looking for? Faulty 02 on the rich bank? Vacuum leak? Fuel pressure?? Should I run the car in open loop and see if it fixes it to eliminate or confirm an 02 sensor problem?

Marc

[0rion]

what did the trims look like side to side? They're gonna be a little different but from the sounds of the plugs I'd say you have some sort of mechanical issue going on over there. Any exhaust leaks on that side? Any certain time it does it? Injector sticking maybe?

[Frost]

Besides a leak, it could be a lazy O2 that is staying low. When they are at the end of their life they will often read falsely low as well. You can force OL in the scanner, reset the trims and log. Just a log of it happening for someone to see,even if the wideband isn't present should go a long way as well. You can alternately swap banks with the O2s to see if the issue moves, but the others should be easier all around.

[Boostd1]

Yup, bank 2 02 sensor is fried. Tuned the car in OL for now until he can get the sensors replaced.

Thanks for the help fellas.