O2 sensor question for my 1st gen pickup
#1
O2 sensor question for my 1st gen pickup
hello everyone, i recently picked up an 87 4x4 x-cab pickup and have a question regarding the O2 sensor. the sensor i have a question about is the one closest to the header in the downpipe. the truck i bought has an O2 sensor there but it isnt plugged in to anything? it has a rubber boot on the end of it that really looks like a boot that would go through the firewall. I cant find anywhere on the firewall that it would have come out of and i cant find a plug that it is supposed to mate with. it has a yellow 4 prong plug on the end of it but i cant seem to figure out where it plugs in at. any help would be greatly appreciated, i can get pics of what i am talking about if it will help. also i was wondering if someone can tell me how to read the codes to see why my check engine light comes on and off periodically. the guy had the head off and when he put it back on he didnt hook up the vacuum lines properly so they were a little out of whack for a short time, they are all fixed now and i did a fresh tune up and fluid change to the truck so i just need to figure out the O2 issue and the engine light and it will be good as new again. forgot to mention it is the 22re motor
thanks
-jason-
thanks
-jason-
Last edited by drpdmazda; 11-09-2009 at 08:32 AM.
#4
Contributing Member
iTrader: (3)
How to read check engine light codes:
- http://www.4crawler.com/4x4/CheapTri...CheckConnector
There should be a plug for the O2 sensor someplace low on that side of the engine. And I think there is only one sensor on that vintage 22RE, don't think the post-cat sensors started until the '90s model 50-state smog engines.
- http://www.4crawler.com/4x4/CheapTri...CheckConnector
There should be a plug for the O2 sensor someplace low on that side of the engine. And I think there is only one sensor on that vintage 22RE, don't think the post-cat sensors started until the '90s model 50-state smog engines.
#5
How to read check engine light codes:
- http://www.4crawler.com/4x4/CheapTri...CheckConnector
There should be a plug for the O2 sensor someplace low on that side of the engine. And I think there is only one sensor on that vintage 22RE, don't think the post-cat sensors started until the '90s model 50-state smog engines.
- http://www.4crawler.com/4x4/CheapTri...CheckConnector
There should be a plug for the O2 sensor someplace low on that side of the engine. And I think there is only one sensor on that vintage 22RE, don't think the post-cat sensors started until the '90s model 50-state smog engines.
#6
Your 1987 truck came with one O2 sensor in the exhaust manifold, and it's a one-wire sensor. It plugs into a yellow connector that breaks out of the wiring harness going to the brake master cylinder cover:
![](http://i169.photobucket.com/albums/u225/toy4run/Toyota%204Runner/IMG_0340-25.jpg)
If you have two four-wire sensors in your truck, you may have a later model engine and/or exhaust system.
![](http://i169.photobucket.com/albums/u225/toy4run/Toyota%204Runner/IMG_0340-25.jpg)
If you have two four-wire sensors in your truck, you may have a later model engine and/or exhaust system.
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