I have a 1987 4Runner 22re with a crack between the manifold/collector and catalytic converter. I would like to just remove the whole exhaust and straight pipe 2.25" to the muffler, seeing as though I only have the one O2 sensor on the manifold. The local muffler shop said that the material from my manifold to the catalytic converter was stainless steel on my truck and he couldnt weld it. I was wondering if anyone knows for sure what it is?

 

since when can you not weld stainless steel? Looks like that guy needs to go back to welding school to both learn how to weld and to identify stainless steel because unless your exhaust was changed before, that pipe it NOT SS. Look for yourself, if it's rusted then it's not SS.

 

You could also try a magnet, if it sticks it is steel, if it doesn't stick it's stainless

 

My thoughts exactly, I think i should be looking for a new muffler shop. Any thoughts on what this will do to performance when I remove the cat and take it 2.25" to the muffler and then 2.5" on out.

 

2.5 is kinda big for the 4cyl's, I run 2.25" straight from my header into a muffler and then 2.25" the rest of the way. No cat. Depending on how much your cat is plugged up, you might actually see an improvement low and high end. Otherwise you might see a slight decrease in low end but a better mid-top end.

 

Cat is orig with 284k on it. I'm hoping to see some improvements.

 

Magnet test. Find a new exhaust shop.
You can weld stainless exhaust tubing with regular old MIG welder with carbon steel wire in it. Done it dozens of times.

:wabbit2:

 

http://www.toyotacatalog.net/M1WebGe...D-9288C800EE01


http://www.toyotacatalog.net/M1WebGe...F-7B8C7BBE4480

 

I thought you could. Those are nice..wish I had the $'s for it.

 

haha yup, you could, but lets put this into perspective here. I have absolutely no clue how to weld. But I know stainless steel can be welded. Might have to be tig'd, mig'd, sticked I have no clue, but I know it can be welded just like aluminum can be. Now maybe the guy meant he doesn't have the tools there to weld it, but that's not what is sounds like he said to you. So take what he said for what it's worth.

 

Exactly, the magnet test will tell me what my next step is.

 

It probably doesn't matter with an exhaust pipe but I was taught to back shield when welding SS to prevent a crystallization which weakens the metal. Probably something to worry about if you are welding the SS cooling pipes for a nuclear power plant but maybe not your Toyota exhaust .

I quote from this link: http://www.weldingtipsandtricks.com/...ess-steel.html

So to properly TIG weld SS you need to have 2 bottles of argon and some kind of jig to back shield the weld.