My 1991 Cherokee started stumbling at traffic lights. Shifting to neutral would calm it down some but it was getting annoying. Then it started to die and was hard to restart. So no more daily driving until I got it fixed.
I pulled the codes with the key trick and got only the 12 and 55. codes. I hooked up my Actron scan tool and all the readings looked normal. I could see the injector pulse width and O2 readings changing just like they should. Occasionally the O2 voltage would go to zero just as the engine died so I began to suspect a fuel problem.
