[lucas1234]

im having trouble tuning my 07 mustang gt , i have a forged 3 valve with port and polished heads, a intercooled procharger psc1 making 12 psi, lunnitie cams, headers and mid pipe.and over sized valves, and im running on 93 octane. we powertuned the car and as far as drivability it would flip flop lean to rich, just back and fourth. we then changed the O2 sensors and it ran perfect for a couple days. one of the guys working at the shop cranked the car pulled it in the shop and killed then an hour later cranked it pulled it out and killed it and the a couple hours later pulled it back in for the night and killed it, the next morning cranked it and pulled it back out and it fouled a plug, so they cleaned the plugs and cranked it back up and it started doing the same thing flip floping back and forth, lean to rich, we changed to O2's again it dosent help, any ideas on the problem, and one more thing i went from an automatic to a standard using the factory auto ecm. i put a tko 600 5 speed

[Trick Tuners]

sounds like the tune needs some work