this is a continuation of this thread: https://www.cherokeeforum.com/f2/los...riving-143263/

replaced the MAP sensor, it helped, but it still runs too rich (i think) and will bog down while driving.
i have done:
throttle body clean
new map sensor
new O2s
plugs cap and rotor

The rear O2 wires were wired directly to the 02, so i pulled a new harness and soldered it on. the code it keeps throwing says O2 sensor bank 1 sensor 2 high volt wire. there is a pending one that is bank 1 sensor 2 heater wire, but it never has actually turned into a code. im at a loss of what to do. i traced the wiring for the rear O2 back as far as i could and found one spot it was rubbing and went through to exposed wires and cut that and put a connector in but it still throws the code and will still start up and idle ok for about a min then run rough and bog down, as well as SOMETIMES doing it at speed. i really need help.

and if it helps, when it starts running rough i read in our code reader that it is leaning out the fuel as much as 30% and the pressure inside the intake manifold will go up as well.

if there are any more questions i need to answer or anything needs clearing up, please ask me so i can try to explain better or more thoroughly. thank you all in advance. my next idea is to check fuel pressure? maybe an unsteady flow of fuel could be wrecking havoc. im not sure.

 

bump so this isnt lost in the abyss haha

 

Won't probably be much help but... I had codes (can't remember which ones) leading to O2 sensors issues. Replaced at least one (I think it was the upstream one). Was still having issues. CEL kept coming back with the same O2 sensor code. changed the O2 sensor again (under warranty). Still same issue. Ended up being the transmission oil dipstick that was leaning against the main harness and had cut some wires. Can't tell you which wire(s) were cut, I didn't do the repair myself at that time. Maybe it is worth checking?

 

yea, i thought it could of been some wires somewhere that are grounded when they shouldnt be. i found one frayed one but still having issues. maybe ill try tracing from the upstream one back and see how far i can get... thanks! having my arm in a sling makes the whole rest of this a major PITA haha.

 

Just my 2cents for what it's worth. To me it sounds like a low O2 reading is causing adjustment of fuel delivery to a lean condition. Did you ever get a code for purge valve or evap canister? Cat blockage? Bad cat can cause bad O2 data. I would have it checked.

 

i havent gotten those codes, but i tried to do a test to maybe show it was a plugged cat? i took out the rear o2 and placed it outside of the exhaust so it would read "clean" air. it didnt throw any codes or hesitate while driving, but i would rather not get a whole new cat just based on this hunch. is there another test i can perform without taking it into a shop? or just run the jeep like i was doing to see if it hesitates or throws a code for a good amount of miles?

 

Most muffler shops will test it for free. Call a few and ask 'em. Or if you prefer you can buy an exhaust pressure test kit. With the kit, you drill a hole in the exhaust pipe behind the cat and check the pressure. Plug that hole and drill one ahead of the cat and read pressure there. Equal readings means no blockage. Low on the rear and high on the front means blockage.

 

ok, sounds good. got something for tom!

today i tested the fuel pressure, it was reading pretty steady around 46. a little lower than the prescribed 49, but within tolerance. even when it started shuddering in idle, it went up and down quickly (as i would imagine anything does when it starts dying) it was still centered around the 46. and when i turned it off the fuel pressure dropped slowly over the course of like 20 or 30 seconds but held steady at around 35. so im guessing nothing to do with fuel delivery.

 

anyone with any further ideas?

 

Have you cleaned or replaced your IAC? Also check all battery connections and grounds. It may not be related to the o2 sensor code. Does it do okay driving? And how is your fuel mileage?

 

ive cleaned the pintle, and i couldnt tell you the milage im getting, i havent calculated it. it isnt RIDICULOUSLY low though (like under 10). i know that much. i will check the connections again but i have looked through them to the best of my ability.

 

Does it idle low and then dies or does it just die... I had the same problem mine stall if park or when i came to a stop .. It ended being the throtle body that was full of dirt and dust.. I got a bottle of cleaner from autozone and used the whole thing on the censors and all inside with the straw... And problem solve... Rpm when up and mpg $$$$$ ...now drives smooth like before... Hope it helps...

 

it idles well for about a min, then will run rough. unfortunately i already cleaned the throttle body... if only that fixed it haha