Printable View
I have installed a trifecta tune on my 2016 impala 3.6 about a year ago. I believe the timing is not as smooth as it should be and there is some low and negative values. Also the fuel trims are very negative. I would like to revert to stock and tune from there but i am not sure how ethanol content affects logs and tuning.
The log is normal for this type of vehicle. Remember this ECM uses ignition timing for engine torque management. Negative trims are not necessarily indicative of any problem, unless you also set bank too rich codes. EVAP purges and O2 sensor self tests will cause negative trims.
Is your car factory flex fuel (does it have a yellow gas cap)?
I bet if he pulls 2-3% from the MAF curve below 8,000hz it will clean up the fuel trims so they aren't as negative.
I have a 2014 lacrosse premium with the upgraded lfx e39a probably the same