I hope im posting this in the right place, im new and dont really know what im doing. Ok well, my mustang has been running very rough for a while now. It almost sounds like it has a cam in it at the idle. It sounds like its misfiring, but no code is being thrown, i do have a P0161 being thrown though. I have changed sparkplugs recently, and fuel filter and checked and cleaned all the coils. Checked the tps, i have cleaned the MAF and throttle body. Checked the IAC.. I also have no fuel pressure when i take the gas cap off, is that normal? When i floor it, the rpms rise very slow which it shouldnt because i have 4.10 gears. Also I have my catalytic convertors removed, and have mil eliminators, had a mechanic say i need to tune it to delete the rear o2s then it would run perfect. Any advice would be great.