trying to pass smog

i want to take my test pipe off and put the oem cat in its place. will it fit considers my catback and downpipe are 3 inch and the cat is 2.5 inches?

 

Yes this will fit, I had a Megan downpipe with the stock cat and Hks Hi-Power catback. Was in the same situation for passing smog.

 

thanks ZeRoMaX

 

Just did what you are proposing 2 weeks ago. I did have a problem bolting the stock cat to my 3" JIC catback. The reason being is because the studs that come out of the cat to bolt onto my exhaust were slightly too big, so I had to dremel my exhaust flange holes… But I bet yours will bolt right up! I have special luck with things lol

 

Forgot to say I switched back to the stock cat because I failed the sniffer in Cali with my ultimate racing 3" cat. Gives me a good excuse to just pony up to the milspec now...

 

I have a cat for sale if you need one