Thus far I have removed the passenger seat and sill trim to expose the connector under the carpet.
Then I removed the heat shield above the Catalitic converter to give more room to work. Now the question.. What type of bolt holds the oxygen sensor in?? Cant see them, larger than an 8mm.. are they not hex bolts possibly?

Insight appreciated.
Roger

Roger:

They aren't botls....There are studs that the O2 sensor slips over. The nuts I believe are 10mm. I strongly suggest that you put some liquid wrench on before attempting to take the nuts off. Also using a fuel wrench is good so that you don't strip the nuts. Stripped=Screwed. Good Luck

Brian

My check engine light never came on. After the tune up and the fuel injection cleaning the thing ran good for about a day, so I went back to the shop that did the FI service and the mechanic said that the next thing he would try was to change the oxygen sensor. I wish that I had done that first because I'm pretty sure that was my problem. My truck runs alot better now, my hesitation problems are gone (at least I hope so). It took about 10 minutes to do, (in the Seattle rain I might add). The OEM part was 100 dollars. topper44_55

Hi Jim, I have an '89 w/ the same engine. The O2 change is a snap. It is easy to get to in the exhaust that runs right under the drivers seat. I bought a factory one, and it had the same connector plug as the original. You just pop a grommet out that goes through the floor near the seat and run the new wires through (you can tell where by following the existing wires). The whole job takes less than 30 min. I didnt check at the local Parts America or Autozone because I wanted something reliable that worked accurately, but I bet they have one. I think I paid about $90 from a Toyota parts wholesale place. They do mailorder. Russel Toyota, (800) 638-8401 Hope this helps, Jason