Hello, I am tuning a 2017 Mustang GT with JLT, long tubes, and IMRC delete (not by me) that was tuned by another shop and told the customer that he could put a few gallons of race gas in a tank with 93 which makes me wonder if he needs O2 sensors. He brought it to me because it was misfiring and running pretty bad. The fuel trims were adding 10% fuel. I tried to do a crank relearn on it a few times which it didn't take and gave the P0315 so I got the stock file for the car and started over with the tune. I added 38% fuel to the MAF and on start up it was within 3% STFT and 0% LTFT. I tried the CRL again which removed the P0315 but now it's acting different. It is not misfiring under part throttle anymore but every time I let off the gas and get back on it now it make a deep bogging sound for a second and then drives just fine. It throws 5 to 10 misfires on HP Scanner every time I do that and then drives just fine. after driving it for a minute again it went back to adding 10% LTFTs again which is why I'm wondering if the race gas killed his O2s.
I think I may have found the issue. Look at the exhaust cam timing on this log. Exhaust cam 1 has no movement the entire time and exhaust cam 2 only moves half the time.
Never mind that. Tested solenoids and the cams are working now. Any advice? Checked IMRC runners to make sure they're not broken. It is misfiring again under part throttle between 1500 and 2500.
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