Good info here! Just did some data logging and I had to trim all the cylinders quite a bit to get my LTFT under -10%. I had thrown "rich bank 1 and rich bank 2" codes along with some misfire codes on several cylinders...so I was well beyond 30% rich on my ODB data log. I right now I'm at 64% injector offset with cylinders 1/3/5/2/4/6 trimmed about -20ms with #9 trimmed about -45 ms and that pesky #10 about -70ms. Before basically only #9/10 were trimmed about -15 and -35ms respectively. Need to do some street driving and check my new timing, W/M, and fuel mapping too since I tweaked all that as well...sure wish my AC was working.
Hi Eric,
I believe you have my fuel trims for comparison on the back cylinders and base set. I throw misfire codes on the 01 car with stock pcm because of the blower/light flywheel -- not the fuel mixture. I have a 96 pcm on the car that gets the miles, but see no sense spending the money for the car that only gets 1500 miles a year.
Misfire codes do not trigger the safe mode like front O2s do.
Not all Roes came with the same size injectors so the base set will vary based on how much fooling the pcm the VEC needs to do.
I follow the 3rd tube argument, but still think it better to sense all 5 and then trim a couple accordingly by plug color. It's really only the back ones that need much work.
.....as opposed to the pcm seeing only 1 cylinder in closed loop (90% of driving) and then having to trim 4 by plug color. Seems safer to only trim one or two by color.
Seems to be working pretty good this AM. Had to dial back in some timing since I had some "audible" pinging last night messing around at WOT. My 140+ mph blast into work logged around a 12.2-12.5 AFR pulling to redline in 4th. Gotta love the Tampa tollways....
If I remember, you landed an old pcm to get rid of the heater codes? Are you running the VEC 3 IAT feature? 12.2 to 12.5 seems a little high to me...especially if not adding fuel when it's cooler with the IAT set up.
But I'll bet 12.2 to 12.5 puts a smile on your face....especially when you escape unscathed.
Steve