s2000james

Hi guys! I have a question regarding exhaust gaskets... I just bought a used Mugen header and the seller included both (Mugen's) exhaust gaskets: the flat one on the engine side and the "donut" one on the cat side. I have asked a mechanic if both these used gaskets can be re-used and he said yes; though Honda suggests to replace these gaskets whenever the header is removed.

I've seen from various threads in here that people re-use header gaskets and that seem to work fine. I figure these gaskets aren't expensive and would like to buy new ones, for the sake of peace of mind. However, it seems that you can't just buy exhaust gaskets from Mugen, my question is really: can Honda's gaskets work on Mugen header? Are Honda and Mugen gaskets actually the same? Honda's "donut" gasket (18229-PCX-003 GASKET, EX. FLEXIBLE) has a inner diameter of 2.5" and this used Mugen one I have measures the same; and I am not sure about the flat one (18115-PCX-014 GASKET, EX. MANIFOLD (NIPPON LEAKLESS) ).

Anyone in here uses their original Honda gaskets when switching to Mugen (or others') header? Thanks guys!

Chuck S

Can't address the exact question but Honda doesn't like to re-use gaskets of any sort and recommends most (if not all) fasteners be replaced with new when dealing with the exhaust system. Recall the shop manual is really for their dealers and dealers will incur extra expenses if the car has to be brought back for leaking gaskets or nuts and bolts.

But new parts are pretty cheap when figured into the overall cost.

-- Chuck

zeroptzero

the gaskets are Honda parts, Mugen doesn't make them. I would not re-use the gasket that goes between the engine and header as they only compress once. I would re-use the donut gasket from the header to the cat as it is a pretty sturdy gasket that doesn't really compress, plus it is a bit expensive to replace. I've re-used my donut gasket a few times without leaks.

Billman250

I have reused the exhaust manifold gasket and donut countless times with issues at all.

Intake manifold I wouldn't try.

s2000james

what I really mean is... if I buy a couple of Honda gaskets, will they fit the Mugen header?

s2000james

Thanks for your advice, zeroptzero!

s2000james

Thanks, Billman, appreciate your input! You must mean without issues.

Chuck S

I've swapped out header-back exhaust systems on two S2000s in the past two weeks (OK, I helped swap 'em!) and in both cases we left the original doughnut gasket between the header and cat. Mainly because it looked like a PITA to get it off and they looked good. Both cars seem to be running well and without leaks.

Sidebar: Systems are Berk 63mm high flow cats and Invidia Q300 dual exhausts. Tip: ensure you can read the "Invidia" plate from the rear of the car or the mufflers won't fit correctly. We were pretty tired after several hours literally Saw-All-ing and grinding the incredibly rusted bolts off the second car that we missed this for about 10 minutes of expletives wondering how the system just slid on the first car and we had so much trouble with the second!

-- Chuck

s2000james

Very well, Chuck. Thank you!