My oxygen sensor on my 89 4runner V6 is toast, and the nuts holding it on are so badly corroded, that they may not be removable at all. They are currently sitting with some penetrating fluid on them, and i am going to tackle them again in another day or so, but in case that doesn't work out, I will need to replace the front down pipe between the manifold and the cat.

Question is, the front down pipes are out of production from Toyota, and the only aftermarket ones I see say they will fit the 4Runners built after April of 1989. Since my 4runner was actually built in December of 1988, am I S.O.L. here? or does anyone happen to know if they are interchangeable?

 

 

Well shucks! Now what about a completely new system from the manifold back? Did they change the mounting points too?

 

 

Mine too was rusted up and rounded off bad. I was able to get out using a deep socket and hammering it on then used a break over bar. I had mine off the truck in a vise and used lots of penetrating fluid.

 

Should be able to get to the nuts with a dremel and small cut off wheel. On my V6 extended cab I used a dremel with flex shaft and a cut off wheel. Took my time working on the nuts and got them off without damaging the threads. Then just used some regular nuts & oil to clean the threads of rust & corrosion. Bought replacement nuts from toyota for final install.

cheers

 

Thank you guys for your input. I am pretty sure I will be able to get them off once i pull the pipe from the car, and if not, perhaps I will try the exhaust shop with welding in a new fitting in. the rest of the pipe appears to be in nice shape, even with 290,000 miles on it.