Hey all! So I have a 2000 Honda Civic EX sedan. I am replacing the exhaust (catback). I’ve run into an issue though. The pipe coming directly from the manifold (contains the catalytic converter), has a 2-bolt flange. Every exhaust I can find for his car has a 3-bolt flange. Can someone give me insight to why this is? And how to find an appropriate exhaust to fit. I’m thinking something was done by a prior owner or misinformation about the car was given to me. Thanks!



attached is the pipe coming from the manifold

 

Because every exhaust you have looked at is designed to bolt up to the 3-bolt flange end of the catalytic converter that bolts up to that 2-bolt flange in your pic. Look at pictures of catalytic converters for your car on Rockauto, and you'll see what I mean.

 

Wait, are you saying the converter is up front on the manifold? Has your car been swapped? Are you sure it’s an EX? Post a pic of the engine, what are the second the digits of the vin?

 

These diagrams show the stock manifold and exhaust system for the 00 Civic EX, except the primary O2 sensor plugs into exhaust pipe A rather than the manifold.

 

That's what it looks like he has in the pic. A converter is supposed to be installed to the flange in his pic.

 

The manifold cover doesn't look the same, and the manifold bolt hole pattern is different where exhaust pipe A attaches. The cat attaches at the other end of exhaust pipe A.

 

Exactly. That looks like the Y7 A pipe, and it seems like that's what OP described. Waiting for updates from OP.

 

The stock Y7 manifold and exhaust pipe A connect with three nuts and bolts.

 

But the A pipe connects to the exhaust B pipe with the same two bolt spring clamp as the ex A pipe connects to the catalyst with. In fact, you can mate up a Y8 A pipe directly to a Y7 B pipe.

 

I was referring to the other end of Y7 exhaust pipe A that attaches to the Y7 dual exhaust manifold-cat unit. It's three nuts/bolts there.

 

I was talking about the pipe in the pic OP posted. It looks like exhaust pipe A and looks like its flange could accept the converter.

 

Oh, I now see and agree with what you and spAdam were saying.

 

Sorry guys! Working the past 2 days and didn’t get around to checking back in. Here’s the other end of the pipe coming from the manifold.

 

Okay I believe I see the issue now. The old pipe the previous owner had on the car had no converter to begin with. He rigged the **** up with basically universal piping and some thick metal wires to hold it in place in some spots. The absence of the cat and his terrible rig up caused confusion. This is my first car that’s not a Mustang and I was unfamiliar with the setup. It seems I need to find a cat now. Thank you all so much! I feel very stupid now 🤦🏻‍♂️

 

Don't feel stupid. There is a fair amount of similarities between the exhausts and previous owners are notorious for molesting the crap out of Honda's. They are so easy to mod and work on that finding virgins is getting harder and harder. As well, if you aren't used to looking that them, you won't know the subtle little things at first. That's where the board comes in and puts it in an easy to digest manner so you can know and identify what you are seeing.

You got it figured out now. That's what matters and I think we helped with that. Kudos!

 

The header is the wrong one for an EX. You have an LX/DX/CX header with the cat converter on it. You need to find an exhaust for a CX/DX/LX sedan or 2dr coupe.

 

Or purchase a test pipe to make up the length.

 

Test pipe may not be an option depending on what state regulations you need to follow. For example, Florida or Mississippi, you're free to do whatever without any real legal problems, but California not so much. Just check and be sure.

 

The car still has a cat. I’m just pointing out that he can use a test pipe to make up the extra length between his A & B pipes.

The legality issue will be if the car is actually an EX and has the stock Y8 in it. Then the cat/manifold he has will NOT be legal since it’s not in the stock location. He will need to get a Y8 exhaust manifold and cat, then bolt that all up to an EX/Si exhaust.

I see a stock secondary HO2S connected to a stock Y7 harness in the last pic posted. I still think there might be confusion as to what trim this car is. OP, what are the second 3 digits of your vin? EJ6 or EJ8? Also, since I’m already asking again, please post a pic of your engine bay from the top.

 

I looked at that pic just wrong. Lol

 

Mississippi has regulations!?!?!? my god....

 

Okay! So this IS an LX. It has the D17. There was a miscommunication with the submodel. The issue now is that I can’t find an exhaust to fit the LX. I can only find them to fit the EX. Can I use a test pipe to connect the two or do I need to swap the header or find an LX exhaust? Is there a way to easily convert? Thanks in advance guys. I really appreciate the input!

 

D16y7*** sorry. Night shift 😴

 

Yes use a test pipe to take up the extra length.