Working toward an end goal of getting a BAR sticker for this thing, so I'm looking for a direct fit cat. I'm just realizing that in all of the swaps I've done over the last 20 years that there's been some sort of custom cat or test pipe used and I have no idea what the stock combo is!

Will one for an EX/Si fit? Integra? Or am I screwed and need to do some welding? I need to retain the stock LS exhaust manifold/A-pipe, and the exhaust is just an A'pexi WS2 (so stock location on that).

 

In order to pass BAR, you HAVE to use an integra CARB legal cat. A civic cat will fail you visually. Every component you use has to be the correct part for an integra (obviously of the correct year). That means the evap system, intake, exhaust manifold, catalytic converter and ecu must all be original or CARB legal replacements. I recently REF'd a b20b in my 97 hatch using a magnaflow "weld in" cat stamped for an integra. I went with the weld in because I'm using a greddy header and apexi WS2 and the length and flanging for the "bolt in" models didn't look like they would work for me.

 

You couldn't just have them weld a custom length extended pipe w/ proper flange?

 

You can modify the exhaust. You cannot modify the exhaust manifold or OEM/bolt in replacement cat. The "weld in" aftermarket cat gives you the ability to match length and flange orientation which is why I see it as being a better option than a bolt in replacement cat that likely won't fit correctly and costs quite a bit more. At least in this case where we're trying to make a bunch of random specific parts fit together without raising a red flag with the REF.

I will say that the REF I saw was EXTREMELY thorough but he didn't give me a hard time about my obviously unprofessionally welded cat. It isn't pretty but he ran the #s and everything checked out so he passed me.

spAdam- I just took a look at your build thread and it looks like you have an obd1LS intake manifold. Is that correct? I think you'll have to swap that for the obd2 type with the evap purge solenoid on top in order to pass visual for the evap system.

 

California love....tryin to keep the environment clean.

 

Yeah I started gathering parts a couple of weeks ago:



I've got a few things left to round up but I'm not in a big hurry since I don't even have a garage yet.

As far as my original question though, that helps. I get the ins and outs of the inspection, but I wasn't sure if the Civic cat would pass or not.

The question remains though, I need to see if I can find the overall lengths of both cats. My welder is staying in Florida, so a direct fit would be the best option since I won't have to negotiate access to one.

 

Drive it down to a shop and have them weld in a cat for a 00 Integra. BAR checks the carb number on the cat.

 

Pretty sure you're gonna need the secondary o2 on the cat, you can probably run the obd2a ecu as well. I had no cel's on my em1, the com port was able to read the ecu just fine.

 

Yep I'm aware of all of the changes that need to be made.

So, weld in is definitely the only option? It's not a huge deal for me to weld something up, I'm just surprised how hard it is to get a simple yes or no: is the Integra cat the same length as the civic cat? No one seems to know.

 

As far as the length, I don't know. It's just easier for me (since I know how to weld as well) to just buy a weld-in cat that is for the right car..I'd rather buy once and get it fitted up right the first time, rather than 'hope' that the cat is the right length.

 

ECU has to be the same year as the engine he's trying to bar the car in. Since his car is '00 he has to run an '00 ecu.

 

Yeah, at least there's a 2.25" in the CARB approved list for the Integra. I'm just going to keep exploring options.

 

A quick google search provided conflicting information. I found threads where people said they are the same size and others with conflicting measurements. My suggestion would still be to opt for a weld in replacement. Even with the added cost of adding the flanges at an exhaust shop you'll still probably be spending less money than you would on the bolt in/direct fit type.

 

Well, it's by year. IIRC, all 00-01 Integras had the same size cat and earlier ones were longer in GS-R (possibly ITR) trim. Can't remember precisely, and I'm not sure what the actual lengths are. I'll try to get the car in the air sometime tomorrow and measure the current one at least.

 

I did a comparison of the A-pipes and cats for all of the OBD2 Integras. The lengths don't appear right (might include protruding studs or something, not sure), but that's what's listed on the official parts database so I listed it anyway.




Still doesn't tell me how far back the end of the cat ends up, but I'm getting closer.

 

I just went through something similar on my car. My setup is a 93 Civic coupe with a B18C1. The exhaust setup is a 00 USDM ITR manifold (basically a GSR manifold) with a 94-95 Integra LS catalytic converter and Yonaka catback. Everything bolted up perfectly.

I have an OBD1 GSR cat, an OBD1 Integra LS cat and OBD1 civic cat in my garage and they are all different lengths. The A pipe part number is the same on the 94-95 B18B powered vehicles as it is on the 96-01 cars. Based on this, I would assume the catalytic converter length is identical OBD1 vs OBD2.

From what I remember researching all Integra catalytic converters are the same length except for the 94-99 GSR.

I just went with the OBD1 cat as I don't need both 02 sensor positions and it was quite a bit cheaper.