what is the size of the stock Ypipe on a 91, at the connection point to the cat? meaning outside diameter? for example, if i were to replace the cat with a pipe, what size would the pipe have to be to SLIDE ONTO the y pipe?

thanks

 

The Y pipe is a pipe in a pipe.... inside diameter is what you need. All the ones I saw were 2" (ID)

 

Tiny?

2" sounds right, or 1 7/8ths

 

more like 2 1/4" Go to parts store & ask for replacement convertor. It will be a slip fit your looking for. Measure that.

 

http://www.catalyticonverters.com/PO...D41158389.html