I have a 1991 CRX HF. All stock except there was no Catalytic Converter when I bought the car. Can I use a Universal one? The reason I ask is I found online, the stock cat which is about $300. and the universal is no more than $100. Aside form the dimensions and the look are there any internal/external properties that differ the two.
Here is teh stock one
Here is the Universal one

 

pm'd you

 

you can do it, but ur gonna need a few things..
88-91 dx/si exhaust manifold
88-91 dx/si small pipe about 10" i believe found right after the down pipe
88-91 dx/si mid pipe (unless ur gonna weld)

mainly because your original mid pipe will be too long and not allow for the universal cat to bolt up properly.

here is what you would need if you dont want to bother with any welding...

 

So basically the only difference is if I want to bolt it up or not.

The person I bought the car from had the stock CAT cut/removed and had a straight pipe welded on from the down pipe after.

I guess I will have the Universal one welded on.