Is it just me or does anyone elses Stang do this. I rev the motor for a friend or my own enjoyment and if I rev it past 3K it lets out some pops on way back down. I have a check engine light due to O/R H-pipe but I really dont think thats it cause the code is just for the rear passenger side o2 sensor so I think it wont change the A/F in the tune. Do I just have to live with this b/c of O/R pipe and Flows or will a custom tune correct this?