Everything I try on this car doesn't work. I've cleaned MAF, throttle body, IAC, EGR, replaced hoses, checked for leaks, replaced alternator, no check engine light, took to an exhaust place said cats were fine, ignition coil readings fine, fuel gauge working fine, NO CHECK ENGINE LIGHT, just done so much to this car. (Yes the check engine light works, was on due to a bad EGR pipe and missing PDFE sensor. I fixed that, light gone.) I have changed spark plugs, wires, and done regular maintenance on it (oil, FUEL FILTER, air filter, etc.).

It jerks and hesitates, stumbles and loses rpm when it's sitting idle in my yard, stopped at a red light, and occasionally when I'm driving it. I had a feeling it was my alternator, so I disconnected the power cord to it. It worked perfectly. I ordered a new one, put it on there, and it's still doing the same thing. Pulley system and serpentine belt have been changed (idler pulley, pulley tensioner).

NO ONE CAN FIGURE THIS OUT! It still jerks, idle changes in sound as it stumbles. Guys at Advanced Auto Parts said the alternator was making a loud whining noise, but it's brand new. It tested fine.

Why is it still jerking/hesitating? RPM dip down, raise right back up. Engine is very strong. Ran seafoam through it, good fuel, fuel injector cleaners… I don't see anything wrong with the electrical wiring coming from the alternator.

Please, just help me. I don't know what else to do. I feel defeated. Heck, I'll even PayPal someone some cash if they find out what the problem is for me. I just can't figure it out!!