MAF / VE auto-correction
Paste a closed-loop datalog and get the exact % correction per RPM×MAP cell from your fuel trims — the math an e-tuner charges for.
Needs closed-loop driving with RPM, MAP, and both fuel trims (STFT + LTFT).
How MAF/VE correction works
In closed loop, the ECU corrects fueling toward stoich and stores the error as fuel trims (short-term + long-term). If a cell shows a consistent +8% trim, the engine is adding 8% fuel because your MAF or VE table is reading airflow low there — so you raise that cell ~8%. Do it, re-log, and the trims shrink toward zero.
This tool bins your logged total trim (STFT+LTFT) by RPM and MAP and averages each cell, so you get a correction map instead of eyeballing a scatter plot. It only fills cells with enough samples. It corrects airflow, not WOT power fueling — wide-open throttle is open loop, so verify that separately with a wideband.