Catalytic converter. What size?? 89 240SX

[Prelude Guy]

Hey all,

As some of you might know, I have a MAJOR bogging issue with my 89 240 SE. I tried replacing many fuel/ignition parts to cure this prolem. NO luck. I think it might be a bad catalytic converter. I was going to upgrade to a Carsound 3" highflow cat when I got my SR20 but I want to have my car running right now until I have enough money to buy the SR.

What diameter Carsound cat should I get?? 2" or 2.25"?? Can I get the 3" cat and make it work with my OEM exhaust system so I don't have to buy another one when I upgrade the exhaust for the SR?? I can get a Carsound cat off of eBay for $55 shipped to me so I am not too concerned about it but if I can save the cash, that would be AWESOME!

Right now, the cat is welded to the downpipe and the OEM cat-back.

Thanks,

Andy

[180fan]

measure your piping there and that's your answer.

[s13sr20chris]

if you can weld flanges then i would get the 3inch.

[Prelude Guy]

if you can weld flanges then i would get the 3inch.

I think it might just be easier if i buy a cat for the stock exhaust diameter. Do you happen to know what size the exhaust diameter is?? I can't believe no one can anwser this.

[s13sr20chris]

been a while since i had a stock 240

[BadMojo]

I think it might just be easier if i buy a cat for the stock exhaust diameter. Do you happen to know what size the exhaust diameter is?? I can't believe no one can anwser this.

I measure the exhaust piping on my car before I got a 2.5" BRM exhaust. It was 2.25", but here's the catch:

I don't think it was an OE exhaust. As far as I can tell, the original owner had a muffler shop replace the piping from the cat back. Now, it's likely that the shop used the same size piping as OE, but I can't guarantee it.