I have a 5.3 LM7 with a SLP 234/228 cam, LS1 intake, and longtube headers. Previously the car had manifolds which I knew would hold it back. It was tuned with the manifolds on it, and after installing the headers and logging the tune I'm not sure where to start dialing it back in.
From a cold start without touching the gas, as soon as the O2 sensors start reading, the STFT start pulling fuel and adding to the negative LTFT until they get to around -18%. Each time the STFT hits the most negative point, it will reset to 0 causing a bit of idle surge, before going negative, then resetting back to 0, it continues to loop doing that over and over. I'm a bit of a novice, but I'd like to learn how to take care of tuning myself, I would log trims and pull the difference from the VE table to get it back in line, but I have a hard time believing that putting headers on it would require me to pull rather than add.
I would appreciate any advice and insight into what might be causing this and where to go next, this is the first cammed vehicle I've tuned.
WhitebirdWIP.hpt
whitbird LTs.hpl
LS1.Layout.xml