Ok so I got my headers on and everything, I had to take off my entire exhaust because none of the A or J or whatever pipe bolts stripped out due to rust(they were basically welded on). So i took the rest of the exhaust off since it was all hangers and it was easy, drilled out all the bolts and now I installed new headers and dowpipe/jpipe/apipe(whatever its called) and need to know if I need a gasket between the cat and that pipe, I went online and all i can find is this o-ring looking thing but neither my cat nor the new pipe has a groove for it.

Cliffnote
-Do I need a gasket between cat and downpipe from headers?
-The only reason I keep calling the pipe an a/j/down pipe is because the guy at the honda store told me I was wrong and the pipe going down from the headers is an a pipe.

 

Yes, there should be a compression gasket between the cat and the downpipe.

If you're not seeing a groove for it, it may be because the compression gasket is already compressed into the groove, giving you the impression that there is no groove.

I re-used the compression gasket when installing my comptech headers with no leak issues.. so I would think you'd be fine. But for peace of mind, you may want to replace the gasket while you've already got the exhaust apart.

 

FYI, the stock compression gasket is smaller then the XS header j-pipe. Measure what you need and Auto Zone should carry it.

 

Well I went out and checked and found that like I though the flange on the headers is completely smooth, no compression fitting, nothing. So what I plan on doing is buying copper gasket maker, the stuff withstands up to 800 degrees or 1000 degrees something like that. Ive already used it on a past turbo setup where the turbo bet the header and as you can imagine pressure was high and it never burst or leaked.

I found that it is actually an a-pipe which is very strange since it has a very j-ish physique but w/e.

Also I bought the obx SS headers, and apart from this little problem I've got nothing but good to say about them. Very high quality, great welds, AND all the welds are smoothed down on the inside of headers. Fit was dead on aswell, so far no problems. Ive got pics close up aswell if anyone wants to see weld quality.

 

Check the cat then, thats where the gasket may go. I may have confused the j-pipe to cat gasket with the header to j-pipe gaskets.

 

I JUST did Comptech headers on my car and I remember everything still.

The CAT does not have the groove in it for the compression gasket. The headers are what had/have the groove in them.

FYI I wouldn't use gasket maker cause down there, there is A LOT of stress due to engine movement and it's only a matter of time b4 the gasket maker stuff craps out on you. I did it with my old ford Probe SEVERAL times, only to fail each FRIGGING TIME.

If I were you I'd get a real copper gasket and cut it to fit and drill the proper holes. But that's just me.

Exhaust and Silicone just don't sound right together, don't ya think?

 

Yeah, it seems iffy but I have had experiance with it before and as long as you let it sit for the curing period (24 hours) it will be fine. I tightened it pretty well and honestly if a compression gasket can hold I think this stuff will too, it gets pretty hard with a little flexibility. Also the two flanges fit very well together so all should be good.

Anywho everything is set and done and now I'm just waiting for it to cure, i'll upload some pics when I take them.

 

Started up the car today, no leaks! happy about that, but my 2'nd o2 sensor(the one connected to the cat) is shorting out! I went to autozone it said bank one sensor two so I got home and put the car in the air tugged lightly on the sensor wire and it came right out so my friend didn't plug it in right. Well after messing with it for a lil it finally clipped all the way in but I still have the CEL. Am I supposed to reset the computer after I did all this? I already did but need help from you guys.

 

Yea, you have to clear the code either with the reader or by resetting the ECU.

 

I'm needing a gasket for the same place and I rather not use the gasket maker stuff.
What real gasket can be used ?

 

Get a measurement and go to Auto Zone/Napa/Advance Auto and find a donut gasket that matches it.