i have had this issue for quite a while... my CEL comes on at random times i also notice that just before the CEL light comes that my "traction control off" light comes on. as soon as this happens if i rev the motor a bit up to 900-1000 rpms the "traction control off" light on the dash turns off

the code that comes up is as follows:
CEL light on constant and is a P0170 lean bank 1
just "traction control off" light only is a P0170 pre-determined A.K.A. P/D

i do have a high-flow cat and muffler and think that its possibly an issue with low backpressure i also have a rear O2 sensor immitator from ZZP
am i thinking in the right area or am i way off

I'm gonna put my money on the sim. O2 sensor. Unless your car is heavily modded, you really shouldn't use one... I can't see why low back pressure could be a problem, even if you did have low back pressure. I've never had a problem with my hi-flow when I had it, so I don't think that'* the issue. I think it'd be useful to scan the O2 readings with a scanner. My money is on the simulator, though...