New to this site and have a question. I alsotried the search bar also. I just bought a 1998 xj limited all stock for a dd. Test drove it and never had a problem. Well on the way home I fired a code so when I got home I hoocked up the OBD2 and checked. Gave me a bad 02 sensor on the upper bank. So went out and picked up a direct replacement from peps, bosch and put the new one in and cleared the codes. Went out for a long drive and now get one for high voltage. Ive checked all the wires and all is good. Jeep runs great and gets killer gas milage but I do notice every so often on startup and while a little cold, if I pull out to leave it will hesitate/sputter but then is fine. Looks like the guy i bought it from put a tune up on it before i bought it cause plugs cap and wires are spotless. Just need help.

 

Run some fuel injector cleaner through it for the sputter, Lucas works pretty good. Helped with mine quite a bit.

 

maybe time for a new fuel filter

 

Im gonna do a full tune-up and see how this does but im still want to know what would cause it to kick on the C.E.L. and say high voltage. Anybody got anything orcame across this.

 

Only thing I can think for 'High Voltage' would be a failing regulator in the alternator.

 

yeah try this first for that. I only use lucas or seafoam, dont get crap like stp or any of the cheap stuff its junk. I buy lucas in the gallons heh. I've used it in every car I've owned along with a hot soak with seafoam and have allways had excellent results. I've actually had the lucas cure noisy valves!

 

The studder i can deal, it only does it if i dont let it warm a little but the 02 sensor kicking on the check engine light saying high voltage on the bank 1 upper 02 sensor is what is getting me. The smog place will fail me do to the light being on plus it will show up on their plu in meter.

 

The store gave me the upper sensor so I put it in still had same problem. so I looked @ the sensor on the cat and duh the wire was broke. my code flashed the same as yours. This was on my 96.

 

hey Bubba I pm'ed ya....i think yer issue might be a 02 wire up against yer exhaust...check that before anything...that would explain yer voltage spike if it has rubbed or is rubbing...just a thought
cameron

 

Thanks guys, I just picked up 2 new ones. 1 for the upper and 1 for the lower. Gonna try the back one and if all is good. Just retern the other.

 

If the previous owner did do a tune up, pull a spark plug to see what brand was used. If it a Bosch platinum or some dumb gimicky split fire or quad electrode garbage, get rid of it and get some good old basic Champion spark plugs. They will be the best plugs you can use for long life and proper performance. If the plugs are of good quality then double check the gap on them.

 

Well did the full tune-up, wich is way nicer than a 95 dodge ram 4x4 360, put both new 02 sensors. Cleared the codes again and did the long idle test to let everything warm up and no code yet. Couldnt testdrive cause my 2yr old daughter is on naptime but the next test will be to drive.

 

Well the light never came on with a long drive, so all is good. Thanks guys for all the hints and info.