Car won't run after O2 sensor change & code reset
Thread Starter
Registered User
Joined: Aug 2013
Posts: 5
Likes: 0
From: Lansing, MI
Car won't run after O2 sensor change & code reset Hi everyone. I'm new here, but have tinkering with my '99 Camaro for several years.
I just ran into a problem that has me absolutely mystified. The back story is a little long, but I would appreciate any advice.
It all started with a SES. The car has been running flawlessly, but I checked the DTC to see what threw the code. It was the good old P1133 (I have long tube headers). I read a bunch of really informative posts on this forum, and went looking for exhaust leaks and all the other simple potential problems that were suggested.
I ended up finding that the wire harness for the upstream driver's side O2 sensor had come into contact with the header and had partially melted. So I cleared the DTC with OBDwiz, pulled the sensor and harness, replaced the melted wires and re-installed.
When I started the car up... it ran fine for about 10 seconds. Then the idle speed dropped way down, it started to sound like it was struggling, and then died.
Several restarts... same behavior. After a the initial few seconds, it starts to choke. I tried giving it some throttle to keep it running... but no good.
Based on the smell and the behavior (throttle killing the engine immediately), My gut feeling is that it is getting way too much fuel. (I can't get it to run long enough to get any good data logged with OBDwiz).
I've replaced both O2 sensors with brand new ones... Put the old O2's back in, switched O2's from side to side... still just runs for a few seconds then dies.
The only things that have changed are the O2 sensors and the DTC has been cleared. I'm banging my head against the wall trying to figure out what's going on. Putting new O2's in should NOT cause the car to go from running perfectly to won't stay lit for more than 20 seconds.
Does anybody have ANY ideas what might be going on here... what I might be able to check to diagnose the condition... etc?
The only other thing that I can think of as a possibility would be that I somehow screwed something up clearing the DTC. I have a custom tune on the PCM. Is it possible to change a parameter with a cheapo OBD scan tool by clearing the DTC's???
Please help. Thanks!
I just ran into a problem that has me absolutely mystified. The back story is a little long, but I would appreciate any advice.
It all started with a SES. The car has been running flawlessly, but I checked the DTC to see what threw the code. It was the good old P1133 (I have long tube headers). I read a bunch of really informative posts on this forum, and went looking for exhaust leaks and all the other simple potential problems that were suggested.
I ended up finding that the wire harness for the upstream driver's side O2 sensor had come into contact with the header and had partially melted. So I cleared the DTC with OBDwiz, pulled the sensor and harness, replaced the melted wires and re-installed.
When I started the car up... it ran fine for about 10 seconds. Then the idle speed dropped way down, it started to sound like it was struggling, and then died.
Several restarts... same behavior. After a the initial few seconds, it starts to choke. I tried giving it some throttle to keep it running... but no good.
Based on the smell and the behavior (throttle killing the engine immediately), My gut feeling is that it is getting way too much fuel. (I can't get it to run long enough to get any good data logged with OBDwiz).
I've replaced both O2 sensors with brand new ones... Put the old O2's back in, switched O2's from side to side... still just runs for a few seconds then dies.
The only things that have changed are the O2 sensors and the DTC has been cleared. I'm banging my head against the wall trying to figure out what's going on. Putting new O2's in should NOT cause the car to go from running perfectly to won't stay lit for more than 20 seconds.
Does anybody have ANY ideas what might be going on here... what I might be able to check to diagnose the condition... etc?
The only other thing that I can think of as a possibility would be that I somehow screwed something up clearing the DTC. I have a custom tune on the PCM. Is it possible to change a parameter with a cheapo OBD scan tool by clearing the DTC's???
Please help. Thanks!
Thread Starter
Registered User
Joined: Aug 2013
Posts: 5
Likes: 0
From: Lansing, MI
Joecar,
You called it... blown fuse. (Man, do I feel like an idiot). I think when the header melted the O2 harness it must have shorted the sensor. The 20 amp engine sensor fuse was toast.
It actually occurred to me at one point to bust out the wiring diagrams and check for potential problems a short in the O2 circuit might have caused. But I got so busy checking other stuff I never actually did it until you suggested it.
Anyway, the car runs now! The IAC seems to have bitten the dust, but that's no big deal. When I started it this morning it would run, but only if I kept the throttle cracked a little. I pulled the IAC and pushed it open manually a little bit. Fired the car back up... and the revs went to 2500 and stayed there.
New IAC on the way... But I'm much relieved... and very appreciative
You called it... blown fuse. (Man, do I feel like an idiot). I think when the header melted the O2 harness it must have shorted the sensor. The 20 amp engine sensor fuse was toast.
It actually occurred to me at one point to bust out the wiring diagrams and check for potential problems a short in the O2 circuit might have caused. But I got so busy checking other stuff I never actually did it until you suggested it.
Anyway, the car runs now! The IAC seems to have bitten the dust, but that's no big deal. When I started it this morning it would run, but only if I kept the throttle cracked a little. I pulled the IAC and pushed it open manually a little bit. Fired the car back up... and the revs went to 2500 and stayed there.
New IAC on the way... But I'm much relieved... and very appreciative
