Long Term Fuel trim questions

[msfyter]

I just added a SLp lid and removed the EGr. Got the SES light of course and the car runs great. I put a predator on it to monitor(my 04 GTO one) On a 70 mph cruise my LTFTs are 16-19% in the positive and at WOT they go down to 7-8 positive. So this means???

[Injuneer]

Probably means you screwed something up when you cleaned up the engine compartment. Something is causing the O2 sensors to think the engine is running lean. The PCM is using the long term fuel trims to correct the lean condition. Could be a "true" lean condition caused by something like incorrect fuel pressure, faulty MAF readings, air bypassing the MAF, large vacuum leaks, etc. Could be a "false" lean caused by misfires, exhaust leaks before the O2 sensors, faulty O2 sensors, etc.

Since you say you are getting good fuel mileage, is would appear to be a true lean condition. You need to find out what you messed up when you ripped things apart. Having the SES light on all the time doesn't help... it masks the fact that you may have multiple issues that would turn it on.

Are the LTFT's the same on both banks of the engine? Are there any other codes being set?

There's very little to be gained by removing EGR, removing cats or removing AIR. None of those really hurt performance, and the EGR system can actually help reduce the chances of detonation (knock) under some driving conditions. I built an 800HP nitrous motor, and kept all the emissions stuff intact.... didn't hurt performanance in any way.

[msfyter]

I plugged the egr motor back in, cleared the 1 code. No other ses codes have come up from a 30 mile drive. Like I said I added a SLP lid and a air hog filter. It idles smooth. Both banks are near the same. I ran 15-16 positive this morning driving to work. I also check all wires, PCV hoses etc . Also reset the battery last night.

[Injuneer]

Is the Air Hog an oiled fabric filter? If so, was it overoiled, possibly contaminating the MAF sensor with oil?

[msfyter]

Its out now, I carefully cleaned the maf, I checked every wire, hose etc. NO leaks, no broken wires no more codes.Like I said the car screams. At 30 mph if I punch it it breaks the tires loose(A4)

[Happy_Dan]

From the little tuning I know, you want to have the LTFT as close to 0 or even slightly under 0. I have been slowly working my way down to that. Don't remember where I read it though and exactly what it all means technically and why.