View Full Version : Think I have a problem?!


eastcoastz
04-19-2008, 10:37 PM
Im not sure if this is the gm tune or not, but for a while now my long term fuel trims always stay + 9 cruising and +14 to 16 when I take my foot off the gas. I NEVER goes - at all. I figured I had an intake leak, but I do not. Replaced the MAF and O2 sensor 1 and stayed the same.

steddy2112
04-19-2008, 10:48 PM
Im not sure if this is the gm tune or not, but for a while now my long term fuel trims always stay + 9 cruising and +14 to 16 when I take my foot off the gas. I NEVER goes - at all. I figured I had an intake leak, but I do not. Replaced the MAF and O2 sensor 1 and stayed the same.

Are you throwing p0171?

All that means is that is has to add some fuel...if you aren;t coding I really don't see how it would be a problem

Red2.4SS
04-19-2008, 10:58 PM
Im not sure if this is the gm tune or not, but for a while now my long term fuel trims always stay + 9 cruising and +14 to 16 when I take my foot off the gas. I NEVER goes - at all. I figured I had an intake leak, but I do not. Replaced the MAF and O2 sensor 1 and stayed the same.

That just means that the ECM is adding that % more fuel than the "expected" value. It is a normal correction that it constantly does. 14-16% is kind of a lot. You may benifit from a tune to get it closer in to 0.

eastcoastz
04-20-2008, 12:06 AM
No codes. Being a tech myself I only see this as the PCM is always just adding fuel. On most cars the LTFTs go + and - 0 to 6. The fact that its always + makes me think somethings up, but since I have the untunable GM Stage 3 PCM I guess I'm screwed.

Red2.4SS
04-20-2008, 12:12 AM
No codes. Being a tech myself I only see this as the PCM is always just adding fuel. On most cars the LTFTs go + and - 0 to 6. The fact that its always + makes me think somethings up, but since I have the untunable GM Stage 3 PCM I guess I'm screwed.

It should be +/- 6 max normally. as long as you can confirm the o2 sensor is good and everything is normal you may just need to tune. perhaps use the old ECM and get it tuned?

Mine have been around -12%, with no codes. It is better to be a tad rich rather than lean.

eastcoastz
04-20-2008, 12:14 AM
I need someone with the GM tune to verify this.

steddy2112
04-20-2008, 12:17 AM
It should be +/- 6 max normally. as long as you can confirm the o2 sensor is good and everything is normal you may just need to tune. perhaps use the old ECM and get it tuned?

Mine have been around -12%, with no codes. It is better to be a tad rich rather than lean.

I got mine down to about 8:)

No more codes...these cars love the warm weather too...first car I've ever had that likes to be hot...

rockkrawler628
04-24-2008, 10:01 PM
I need someone with the GM tune to verify this.

ive got the gm stage 3 but no tech 2