rusted oxygen sensor

Aloha All!

I have an 88 toyota 4runner 3.0 v6 that gets 300 miles to the tank that is in need of a new oxygen sensor. It puffs a little black smoke everyonce in a while and runs rich when it wants to. Sometimes I get 240 miles out of the tank. From all the info I have it seems like the o2 sensor, especially since here in Hawaii there are no emissions laws or checks. The problem is that the bolts that hold it on are totally rusted out. I cant get it out. Does anyone have an idea for me. Thanks

I just did mine last year as my 89 was running pretty rich as well, and you know the nuts on mine were rusted really bad as well. I used an oxy acetaline torch to heat up the nuts and slowly work them off. This is a pretty common technique but it gets a bit touch and go. If the nuts are too hot you can strip the threads off the bolts and if they are not hot enough they won't budge. But I did get mine off and got new ones on again as well. Not sure if I could do it again mind you but it worked this time.

You could drill the bolts out from underneath and just replace the bolts and all with the new sensor? I actually used a sensor off a 1991 4Runner, the plug under the seat was different but I just spliced it with the old one. It worked no worries and it actually helped my mileage from before the sensor went.

You may want to check your Mass Air Flow Sensor as well. Could make your truck run rich. I did both. Again I used a 1991 MAF but the plug was the same.

Hope this helps.

let me know how it goes. mines are rusted too.