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O2 sensor question 1987


crazycory1
08-26-2005, 11:45 AM
I have a 1987 s10 4.3l. It has a single wire O2 sensor. Its been running ruff, so I went to replace the O2 sensor.
I noticed that if I unplug the O2 sensor and let it run, it doesn't cause the ecm to throw a code. Is this normal? Shouldn't it detect that the wire for the O2 sensor is open? Thanks for you help.

Bads Crew
08-26-2005, 07:24 PM
I have a 1987 s10 4.3l. It has a single wire O2 sensor. Its been running ruff, so I went to replace the O2 sensor.
I noticed that if I unplug the O2 sensor and let it run, it doesn't cause the ecm to throw a code. Is this normal? Shouldn't it detect that the wire for the O2 sensor is open? Thanks for you help.

It won't happen in an instant. It will take a while for the computer to pick up on it. Make sure if you change it to disconect the battery for a few min to reset the computer.

Bads Crew
08-26-2005, 07:33 PM
It won't happen in an instant. It will take a while for the computer to pick up on it. Make sure if you change it to disconect the battery for a few min to reset the computer.

I just had a thought. My 87 4.3 had a problem with it running ruff also. I found that the base gasket under the throtle body was leaking I changed the gasket and it smoothed it out. 4.3 is know for this. you can check it for a leak using a small propane torch used to solder pipe. just unscrew the flame tip from the end of the torch. put a piece of rubber hose over the end of the tube of the torch. Crack the valve on the torch and run the hose along the base gasket, If the idle kicks up the base gasket is leaking. Hope this helps.

OverBoardProject
08-28-2005, 06:52 PM
I just had a thought. My 87 4.3 had a problem with it running ruff also. I found that the base gasket under the throtle body was leaking I changed the gasket and it smoothed it out. 4.3 is know for this. you can check it for a leak using a small propane torch used to solder pipe. just unscrew the flame tip from the end of the torch. put a piece of rubber hose over the end of the tube of the torch. Crack the valve on the torch and run the hose along the base gasket, If the idle kicks up the base gasket is leaking. Hope this helps.

A can of WD40, with the straw on does the same thing and is probably safer

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