My cat needs to be replaced. I am having difficulty telling which one to buy. I'd like a high flow cat and am not interested in going with a test pipe. 93 Del Sol, B20 with Acura type R header and Tanabe cat back exhaust. There is one 02 sensor before the cat. Thank you.

 

You'd want the same diameter as the header or a little larger and same diameter as catback pipe or a little smaller. Don't let flow widen out and narrow again but widen a little overall is ok. I put a Magnaflow cat on DC 4-2-1 header of the same diameter and Apexi catback of same diam. Always has passed smog for~ 10 years.

 

Where are you located, do you have any emissions testing?

 

I'm in virginia but the car is over 25 years old so no emissions testing.

From what I can tell without taking the old cat off yet is the header is 2.25 diameter and the piping of the exhaust is the same. So a decent hi flow cat with the same diameter would be best. I'm just having trouble locating one.

 

Just curious, what does this^ mean? Do you still need to have the car inspected for basic safety and for CEL codes, but not tailpipe exhaust testing is done?

 

that's correct. Safety has to be done each year but no emissions if car is over 25 years old.

 

Which integra type r header do you have? if its a US header, you can probably just get one like a magnaflow cat on rock auto that should typically match up with your tanabe catback. It sounds like you want a bolt-on solution?

Just watch out for the cat and their flanges not matching with your catback and header. Some may be for d-series and others for b series and you'll have issues getting it to match up. If the cat has a rotating flange you should be ok.

 

If the header is one piece, it's the 2.5" outlet JDM 98 spec one.

This is the cat that I would recommend for that setup:


There is an OBD1 version also, the difference being the lack of a bung for a downstream sensor. It's sized for a 4L engine and is the same configuration as the one recommended for years by several header manufacturers (I think SMSP or Hytech or someone like that used to take the 49 state ones and seam weld the heatshields for durability and re-sell them). I recommend spending the extra change and getting a CARB certified one, even if you don't have emissions testing. I did the research a while back, part of the certification is the requirement of a longer warranty and higher precious metal content... they actually are constructed a bit better and will last longer than the federal versions.