Thread: Jacked Up Fuel Trims w/Scan

I went from a Front PLOG, and DP to headers last week.

Before I had good trims thanks to the MAF tune... but now I notice at idle my LTFT's are 16.4025

So I figured that I maybe I need to do a VE Tune. When I unplug the MAF I get Lean results not pig rich like expected.

I abandoned the VE Tune for the moment, however when scanning... on WOT I lock in at 0 every time.

Should I just scale the %#@! out of the MAF for the idling frequencies? Or should I put a DHP BIN on there and completely start over?

EDIT: Recent scan added RACETRACK_10-27-2008_9_26_51_A from lawngoose -- Scan Depot dot net

One other member mentioned to me, that I could have a exhaust leak (which I believe, since its pacesetters) and fresh o2 could be getting to the o2 sensor.

My MAP(kPa) looks similar to other scans, so I think its ok, but I will double check all vac lines to be sure.

Thanks for the post!

Welded the pacesetters, fixed a small egr plate leak... reset trims.... still reading +16 on idle.

Next we plugged the exhaust to see if it would get richer... it did not.

The o2 sensor has already been changed once... and I do have a zzp extension harness.

Any ideas or suggestions?

You've still got a vacuum leak somewhere.

Or... have you looked at this (not sure if it applies to you)? Do you have your rear O2 deleted?

http://www.grandprixforums.net/f65/r...ewer-7092.html

Thanks for the post... I have a rear o2 sim, not deleted.

Another member pointed me here.... they call it the "16.4 Club"

Odd LTFT behavior on 01 GS - HP Tuners Bulletin Board

Interesting.... that may be it. I am emailing them now.


EDIT: Got a reply back from ZZP, they advised me that the o2 extension I bought for my front o2 sensor will work.