Just got my B18B1 running in my EF hatch. I’ve got a 4-2-1 header and an eBay special stainless exhaust. There was no cat or exhaust on the car when I started.

I plan for this to be a daily driver and am trying to cut down on the noise so I’m looking at the bolt on MagnaFlow cat (22637) from Autozone. It’s under $200, so not bad considering most test pipes I’m
finding are around $100.

As for fitment, I’m not sure if they’re all standard size/length or if I have to get one that fits the hatch or fits the car the B18 came out of? Trying to avoid welding or taking it to a muffler shop since the front end is still in pieces while I wait for some other parts.

 

Get it for your car. It's all the same fitment.

Like you don't change your cat when you do a B swap. So why would you get a different cat now.

 

Using the search function here confused me a bit with being able to bolt on a cat. This car was basically a shell so I’m piecing together like Frankenstein. Some said the stock cat wouldn’t fit up to a B18B1 header without modification due to the flange being affixed in a different manner.

Since my motor is out of a 98 Integra and I’ve used a bunch of DA Integra parts, I figured that one might work. Not to mention, the 91 civic cat is $150 more and not available anywhere in my area. As long as they’re the same length, I assumed it would work.