Are the Y-pipes made of stainless steel and if so, which alloy would they be made from (304??)

Thanks.

 

No, they are not stainless steel.

 

Pretty sure everything but the cast iron exhaust manifolds are stainless.

 

Come to think of it, the y-pipe I pulled off last year (which was starting to rust) was from the Hooker Cat-back I installed in 98. I withdraw my statement since I did not have the factory y-pipe anymore.

 

the y pipe that was on my 97engine was stainless. more than likely its 304, i think most auto manufacturers used 304 because it welds good,bends good, and has a high resistance to corrosion..

 

the most commonly used I've seen is 409. It has the anti-rust properties of stainless, but it will turn a rusty color, sort of an orange patina. 304 will stay mostly silver, but with a lot of heat it goes to a nickle-blue color

 

Whatever was cheapest- remember, the exhaust system, at least to the catalyst, was part of the emission system, and had to be warrantied to at least 10 years or 100,000 miles- GM didn't want to have to replace those parts under warranty-