[Lawhoc]

I am new to Mustangs. I took a perfectly fine 2006 GT 4.6 V8 (automatic) which ran perfectly and, it appears, I screwed it up. I added a K&N Tornado CAI, JBA stainless longtube heades, Magnaflow high-flow cats, and Magnaflow mufflers, plus a Hypertech III tuner. I keep getting codes -- not always the same ones, sometimes opposite -- like 2198 & 2196 (rich, or sensor stuck rich), 2195 &2197 (lean, or snsor stuck lean). Usually "just" codes, but eventually a CEL. And sometimes, but not enough,no codes at all. I changed the forward sensors. I have been tuning for 87 octaine (Ford recommends 87, and Hypertech graphs show almost identical lines for 87 & 93), but I am going to try a 93 tune. I am at the point of taking it all out and replacing with stock (I still have the headers and air intake system available).

I would appreciatehelp. TIA.