Hi All,

I tried a search but couldn't find specifics.

I am looking to replace a bad cat on a 2000 2wd 2dr. I have measured the pipe. The inlet pipe seems to be 2.5" (outer diameter), but the outlet is a bit larger at 2 5/8".

I took a piece of paper and wrapped it around the pipe. Made a mark on the paper. Then with some simple c=(pi)d, was able to accurately measure the diameter.

However, when looking for Universals, they all have a 3" in/out for the 2000 Blazer. When searching for the 2001, I can find a 2.5 in/out size.

I am planning on clamping it temporarily, then later having it welded.

Will the 3" in/out work? Or will it leak.....

If I get a 2.5", it should fit around the inlet pipe, but I am not sure it will fit over the outlet.... perhaps put the cat outlet into the rear pipe?

Any help appreciated as I will be ordering the parts online and would like to reduce the possibility of having to return it. The car is used for everyday commute and can't have too much down time.

Thanks in advance.

 

I ordered a 2.5" in/out Cat....

I will post updates here for those who might have the same issue.

 

If I remember correctly it is a 3" in and a 2.5" out. What you could do is just get a 3" to a 2.5" adapter and add it that way. That is what I plan to do if I ever replace my converter.

 

How about the pre-cat? Did you leave it unchanged?

 

Sorry for the slow reply.

Correct, we left the pre-cat unchanged. We cut out the cat only. We made the cut just before and after the 'flare' on the inlet and outlet pipe, either side of the cat.

The universal cat inlet fit fine, but we had to use an adapter for the outlet.

Hope this helps...