I have a1995 ford mustang GT 5.0. recently I was reving my engine, and just shortly after my car started bucking and hesitating. Almost dieing at a complete stop. If the stop was long enogh it would stop. I have changed the EGR valve, the IAC valve and the fuel regulator. Also I have replaced all of the hoses that go to the upper intake and the upper intake gasket. I just cleaned the MAF sensor with MAF sensor spray cleaner and now the the check enging light is on and it hesitates when I drive. but the rpms are steady as to where before they were all over the band. any Ideas

Ck eng lite on, or service engine soon mil lamp on. So you need the codes run. You have a hesitation, but when accellerating from what, a stop? You must have been working in the right area, and you can make it to the Ford service area. You can ask them about updates, and sticky throttle bodies, and service bulletins. You can research enginecodes.com when you know the results of that test.

If so indicated after all their q&A, the ford service recommendation will need to read and write down what codes are stored in there and reset. Then a drive cycle would follow. If there are HEGO codes, you need to know before. That's eec-v right ? With a mil lamp lit, it will be in FMEM. If it does not get recorded and reset, it can go limited operation and eventually foul the plugs.

HEGO means: heated exhaust gas oxygen. FMEM means: fuel monitoring effects management FORD means :first on race day, hahaha

Correction: (FMEM) Failure Mode Effects Management This is most oftentimes referred to as limp-in mode.This mode is used anytime a sensor input is missing (disconnected or loose harness) or the sensor is out of range (too high/too low) When either condition occurs,the cel/mil comes on and the ecu substitutes a fixed value for the missing/out of range sensor signal,so that the engine will continue to run, until you can have it repaired.It may/ may not have driveability issues during this time,but it will normally run well enough that you likely wont notice much difference.Once the missing/out of range sensor signal is restored,the cel/mil will turn off and the system will go back to normal operation.