I have a 1992 Jimmy with a 4.3L in it and when i got it i replaced the O2 sensor as i was getting an engine light and fault code for that and then took the vehicle and it passed my mandatory emmissions test here in ontario.
About a month later i got another fault code - tps - also replaced that and no more fault codes BUT
i am getting a O2 sensor fault code again. I took it to a muffler shop and got the Manifold rings changed and i thought they may have bumped the o2 sensor so i changed it once again - lasted two weeks now the code is back.
I am believing its a real code as when i have it the vehicle sputters and almost stalls occasionally.I am using a good brand name of sensor (Bosch) and am paying 75 bucks a piece for them and do not want to continue to replace them every couple weeks or so. The Jimmy has over 300,000 kms on it but has had the engine replace with one with about 130000 on it.
Other than the four wheel drive not going in and it being a real pig on gas and i can live with those things - the only thing wrong with it is this O2 sensor problem.Oh when i do replace it, the jimmy quits sputtering and runs well til i get the engine light and fault code again.
Has anyone had similar problems with this year and make of vehicle and if so do you know what causes the repeated O2 sensor failure.
( converter must be ok as it passed emmissions with excellent rating)

Trouble codes don't tell you to replace a part, they tell you what circuit to check. What trouble code did you get?

Trouble codes don't tell you to replace a part, they tell you what circuit to check. What trouble code did you get?


I got the ecm trouble code 44 - 44Oxygen sensor voltage was under 0.25 volts for 50 seconds of closed loop operation
when i replaced the sensor each time and reset the code by removing the battery cable and putting it back on , the jimmy ran fine for a couple weeks the second time and a couple months the first time. Between these two times i had a fault for the tps and i had that replaced at a local garage and had the rest of the sensor readings ( thats what he said he did anyways ) checked there also and the mechanic said they were all ok.

[quote=billyjack]I got the ecm trouble code 44 - 44Oxygen sensor voltage was under 0.25 volts for 50 seconds of closed loop operation
when i replaced the sensor each time and reset the code by removing the battery cable and putting it back on , the jimmy ran fine for a couple weeks the second time and a couple months the first time. Between these two times i had a fault for the tps and i had that replaced at a local garage and had the rest of the sensor readings ( thats what he said he did anyways ) checked there also and the mechanic said they were all ok.
oh and billyjack - john Hutchings same person i just got my name on here today

Code 44 Oxygen (O2) Sensor Circuit (Lean Exhaust Indicated)
Your O2 sensor is reading a lean exhaust.
Check for exhaust leaks, vacuum leaks, low fuel pressure and maybe contaminated fuel.

Here's where you check the fuel pressure...
http://i131.photobucket.com/albums/p288/Clunk_/Image033.jpg

Code 44 Oxygen (O2) Sensor Circuit (Lean Exhaust Indicated)
Your O2 sensor is reading a lean exhaust.
Check for exhaust leaks, vacuum leaks, low fuel pressure and maybe contaminated fuel.

Here's where you check the fuel pressure...
http://i131.photobucket.com/albums/p288/Clunk_/Image033.jpg Exhaust is good - perhaps a vacuum leak or fuel pressure may be it then -will check them tomorrow if its a little less frigid outside and if my tester fits the connection on this engine for the fuel- im hoping its not a vacuum leak cause i might be days finding one of those- thanks for the prompt replies

Exhaust is good - perhaps a vacuum leak or fuel pressure may be it then -will check them tomorrow if its a little less frigid outside and if my tester fits the connection on this engine for the fuel- im hoping its not a vacuum leak cause i might be days finding one of those- thanks for the prompt replies
OOPs - i was in the jimmy today waiting for wife to come out of doctors so put the little tool in the plug in for the ecm in it. Found i have two O2 codes - 44 and 45 and when i checked the ABS codes its got a multitude of those - 12,25,27,28,31,32,62and 65 butthe brakes still seem to work fine so hopefully they are nothing too overly serious as long as they only affect the abs and have nothing to do with the other stuff. With both O2 codes one for rich and one for lean should i be checking something else or still vacuum leaks exhaust leaks and fuel pressure?
Its still mighty chilly in ontario so i havent tried to hook up my fuel pressure tester and may have to pick one of those up on payday here that has the right fitting for the Jimmy but hopefully by this weekend it will warm up to a spot where your fingers do not start hurting in less than five minutes out there.

ABS codes 25-32 are wheel sensor related. 62 is an internal valve issue inside the ABS controller and 65 is a shorted or open ABS motor relay and might be related to your 62 code.

I'm lost on the 44 & 45 O2 sensor codes together unless one was set weeks ago and the other later. You might try taking the battery cables loose for 20 minutes then reconnect to reset the codes and see what pops up again.

As Chris mentioned, check fuel pressure and leakdown rate. Key on, engine off, fuel pump running: pressure must be 60 to 66psi. After the pump shuts off, pressure must remain above 55psi for 3 to 5 minutes. Post your results.

As Chris mentioned, check fuel pressure and leakdown rate. Key on, engine off, fuel pump running: pressure must be 60 to 66psi. After the pump shuts off, pressure must remain above 55psi for 3 to 5 minutes. Post your results.
Thanks , i am on night shifts right now and just got home and have one more to go then its weekend for me here so i will call my friend that i know has a pressure tester that fits the Jimmy and get him to do it Friday and i will post what i get then.
Guys Thanks for the help on this as its got me stymied.

do you know the exact reason behind your 4x4 not going in? I ask because this could be related to a vacume leak also...check the smaller line out of your upper intake (in the same area as your brake booster hose between the firewall and intake) I had mine crack there before and it caused the 4x4 to stop switching...also it caused the heat position switches to stop switching....just a thought..

do you know the exact reason behind your 4x4 not going in? I ask because this could be related to a vacume leak also...check the smaller line out of your upper intake (in the same area as your brake booster hose between the firewall and intake) I had mine crack there before and it caused the 4x4 to stop switching...also it caused the heat position switches to stop switching....just a thought..
I am not sure on that one - when i got it four wheel was working then first snow there i tried it and when i took it back out it banged or thudded but i have never checked it out but i know its not going in now and ya know i would be afraid to drive it in four wheel as it sucks so much gas in two wheel i would have to attach a gas pump to the rear hahaha.SInce the shifter still works i assume its vacuum line or fuse for this but once again not sure. Supposed to be at the garage today and came down with the flu but if i can get it on a hoist i wanna look under it anyways at the four wheel stuff

Sorry i havent got back to this forum earlier - took the Jimmy to my friend with the garage and his pressure tester dont fit this truck same as mine so on tuesday its going to a garage here and when i find out what was causing a combo of lean and rich o2 trouble codes i will post it on here

Your pal with the garage can also test '98.5-'02 Dodge Rams w/Cummins diesel $$$ with the same tool to check yours if he wants to make a $40 investment to his toolbox.

OK finally got the Jimmy to a garage on Tues - they ordered an AC delco 02 sensor for it and today they put it on. They said the sensor i had installed is defective - not sure if i can put the brand name in here or not but its a usually "reliable brand name" so i returned that one. Drove the Jimmy around town a bit and so far no engine light. Mechanic that put it in said if that doesnt do the trick possibly a small internal intake leak but he thinks the sensor change will fix the problem. Thanks everyone for the advice and help

Ohhh the four wheel drive not going in automatically is the switch on the passenger side fender that allows it to shift on the go - unplugged it and nwo can change from 2wd to 4wd with truck shut off in park so for now thats a fix and at least i know theres not a problem with transfer case that i can detect. I am gonna leave that unplugged til i get to my most fav auto parts store ( scrap yard ) and pick up another switch.

Good work, thanks for the updates.

OK finally got the Jimmy to a garage on Tues - they ordered an AC delco 02 sensor for it and today they put it on. They said the sensor i had installed is defective - not sure if i can put the brand name in here or not but its a usually "reliable brand name" so i returned that one. Drove the Jimmy around town a bit and so far no engine light. Mechanic that put it in said if that doesnt do the trick possibly a small internal intake leak but he thinks the sensor change will fix the problem. Thanks everyone for the advice and help
Its been over a month now probably like about six weeks and the Delco sensor is doing the trick - the two bosch ones must not have been compatible with this particular truck.