Hey guys For the past couple of weeks ive been having odd issues with my 1997 jeep tj 4 banger.
it started with my upstream o2 sensor failing and the jeep having a rough idle.
replaced the o2 sensor and it drove fine for about a day.
rough idle came back and so i placed it on a scanner, fuel system to lean and to rich came up. checked the o2 sensor connection and found power steering fluid in the connection for the pcu.
after a bit more troubleshooting i found that my power steering pressure sensor had failed and was passing fluid throuh wires and into my o2 sensor checked the downstreem o2 sensor and it also had powersteering fluid in it.
out of curiousity i checked the pcu and sure enough there was power steering fluid in the first connection from the right.
I have replaced the power steering pressure sensor and vaccumed all the connections including the pcu then sprayed them with contact cleaner.
rough idle still persists and is running very rich. could my o2 sensors be pooched ?
also can anyone shead light on this BS !!

 

you could try clearing the memory by draining the residual charge from your electrical system. you can do this by disconnecting your battery and touching the two wires together for about 10 seconds or so. this will drain the residual electrical charge from your system and erase the memory on your computer. when you fire it up again, it will write a new fuel delivery program to replace the "too rich/too lean" program that it was using when your sensors, etc. got contaminated...

i had my upstream o2 sensor fail on me and had a very rough idle, even stalled out a couple of times. problem persisted after installing the new sensor. a buddy recommended i try draining the electrical system to wipe the board clean (so to speak,) and it's been running like a top ever since. i used the above method on his recommendation...

note- you will likely see a small spark between the two cables when you touch them together. make sure there are no flammable vapors present when you do this just for safety's sake...

-another way to do this is to isolate the ground (negative) wire from the battery for two minutes. (according to my shop manual, anyways) basically the same idea...

give it a try, it may just be the ticket...
good luck! let me know if it works for you...

 

...well, did it work?