LTFT reading oft

[mike7792]

So this is my first time logging or trying to read the fuel trim readings and what not on the oft.

I know I've got an exhaust leak at the header to overpipe flange and also a small one on the front pipe to midpipe flange

What I've been noticing is a constant negative ( - ) reading for my LTFT reading at idle and while moving
It flucutates between -3 to -7. It usually sits at -7 at idle or when im not moving.

I tried recording today with the oft so I'll try posting a log asap.

What does the constant negative reading mean? How bad is the exhaust leak.?

The afr readings were a constant 14ish?

I have a tomei uel with stock OP+FP with perrin 2.5 cbe

EDIT: Here's the datalog I managed to pull. It's kinda all over the place with bad traffic

http://datazap.me/u/mike7792/log-145...9?log=0&data=1

[phrosty]

Fuel trims will fluctuate depending on fuel and temperature. Probably not something to worry about.

It really depends on where your leak is, but in my experience you'll see an idle trim that is wildly different from driving. i.e. a -10% LTFT idle and a 0% LTFT while driving -- and not one that slowly lowers due to heat soak, but one that instantly bottoms out. My theory is that a leak has a fixed volume of air, so as your load increases the overall % affected by the leak becomes smaller.

So, if you're seeing a steady -3% to -7%, you're probably doing alright.