Fuel trim curve doesn't seem right

[ericem]

Seems like when I check my fuel trims. Lets say 1-7. Sometimes it is consistently increasing so -5.5, -5, -4, etc etc. Yet sometimes they are all over the place like -5.5, 5, -1, 14. How does that happen? Tried replacing the o2 sensor same sort of symtoms but I didn't reset the ECU this time I did and it seemed to be fine after driving around went back to like -3, -2.8 , -1 etc etc.

What would result in this? Exhaust leaks? Could a bad fuel pump not given consistent pressure create a problem?

Fuel economy is definitely not nearly as good as it was when I bought the car which really sucks

Octane factor now stays at 100% all the time.

[BSOD2600]

Being most don't know about the various fuel trim tables, you're not going to get very many/educated answers

I believe the stock fuel trims have a range of -20/+14.7. Do you have the stage 2 v3 chip, which has a -50/+50 fuel trim range? Here are a few random examples of my trims over the past months... octane factor bouncing all around. Until your octane factor is a solid 100%, I wouldn't pay much attention to the trims, as long as they're all within reasonable ranges, until it completely learns.

[ericem]

im back to stock and covered the knock sensor wiring with high temp rtv. Octane factor always at 100%. Replaced my exhaust manifold and i think this one is also leaking at the crossover.

[BSOD2600]

Oh yea, forgot to mention that stock fuel trims are in the negative range, while with the chip they should be positive (per mike @ rev in various threads over there).

[ericem]

Replaced the crossover pipe car seems different. Next will replace the fuel pump, THEN if needed injectors.

[ericem]

Update popped in some other injectors I had, sprayed a CRAP load of seafoam still getting + fuel trims as high as 14.... SO I am thinking time for a fuel pump Octane factor always 100%, and no knocking, and boost is there just not as much power as I would expect.

[BSOD2600]

Fuel trim with the stage 2 chip is +14.7 for a few cells? If so, Mike has an updated chip that raises the trims. I bet your idle bounces after sitting for a while too...