brcampbe

iTrader: (1)

I just ran a scan on my car because I think it is running rich, and my LT fuel trim for Bank 2 sits at 16.8% in open cycle, while Bank 1 sits at 2.2%. Is this bad, and what would cause a condition like this? This was at idle with my car running for a few minutes.

Also, I thought it was perhaps the 02 sensors, but they seem to be at normal activity on my scanner. Should I look at the plugs, wires and perhaps the injectors?

Frost

iTrader: (45)

A split that big is either a decent size leak in the pipe in or around bank 2 (the side that is trimming high) or possibly even a misfire on that side of the engine. Other things can cause it as well, but that's what I would look at firstly.

pajamasam

iTrader: (6)

Couldnt a faulty o2 sensor also cause this?

brcampbe

iTrader: (1)

This is driving me nuts, I have looked all over for exhaust leaks and vacuum leaks to no avail. How do I tell if it is missing? It doesn't have any of the tell tale signs other than the crappy fuel trim. It only stalls out on me sometimes at a cold start, but I think that is just the nature of the cam I have. Could it have something to do with my injectors on that side?

joecar

After checking for air leaks...

swap the front O2 sensors bank-to-bank and observe if the trim follows the sensor or if it stays on the same bank.

then swap the injectors bank-to-bank and observe the trim.

2TR

Yup just like a meachanic would do instead of chasing his tail looking for the unknown.

2000_SS

iTrader: (24)

i've got a similar problem with my car right now. Bank one trims are WAY up there while bank two is right about where it should be. exhaust leaks can definately cause this problem, that's where i'm looking next. i've already swapped the O2's and injectors, the problem stayed in bank one. i DID have a leak around the header flange, fixed it, and the problem still exists. i also changed the plugs, TR6's gapped at .035".

i haven't had time to mess with it any more. i'm going to put it up on jackstands this week to get my new Quicktime bell housing installed, at which point i'm going to go over the exhaust with a fine toothed comb. i'll post my results, if any.

i'm curious as to what else could be the cause of this issue, if anybody has suggestions.

EDIT: forgot to mention, FWIW, the car runs fine in open loop, closed loop is where it goes stupid AND sometimes, it runs fine too...

brcampbe

iTrader: (1)

Ok, it is not the O2 sensors. I could not switch them bank to bank, since the passenger side cable is significantly longer than the driver side, so I bought a new Bosch one to try. It is actually worse with the new Bosch than the AC Delco that was on it, now it's reading 22.5% instead of 16%. Looks like I need to look at some other options. The intake manifold has no leaks, the vacuum lines look good, I guess it could be the bullt cat on the driver's side or a faulty header flange. Will post an update after further diagnosis.

94GreenMachine

iTrader: (16)

I'm having the same problem and it's causing a P0300 which in turn causes other problems like the trans not staying in lock up on the highway, etc. Anyway, was wondering what the results and/or resolution was to your problem in hopes it may help me, etc. Thanks.

MontecarloDrag

iTrader: (3)

P0300 is misfire and it will make the O2 readings be a false lean. You need to first fix the misfires then deal with the trims

bootlife

My mass air was liein to the computer, had to swap it out, easy to over look but watch it close at diff rpm n see how the air % is reading mine was 1% at any rpm and I had no short term fuel trims. Hope this helps