I have a 1996 mustang Gt 4.6 I have replaced the MAF, ambient air sensor, new plugs, new coil packs, new wires. The car is running Lean and surges RPMs at idle. It goes from 1000 RPMs down to maybe 400 RPMs then surges back up to 1000 RPMs and starts loading up and I give it gas and all kinds of extra fuel is burning out of the exhaust. It has no check engine lights and I checked the wiring and had it tested for codes. It says MAF sensor circuit low input and also says random misfire...

1996 Mustang Gt running lean