3" downpipe -> 2.5" catback gaskets?

sid

sid

Greenie N00B Member
What gaskets do i need to match a 3" downpipe to my 2.5" magnaflow catback? I asked CP-E and was told that ill need the 2.5" gasket. Anyone know the part number for this? Also, whats with the donut style gasket?
 
The donut style gasket that it comes with should fit with OEM cat back as well as 3" which is why it's donut style.

Wait you paid for a 2.5" aftermarket catback? Please tell me you replaced stock with that because it rusted.
 
Awafrican said:
The donut style gasket that it comes with should fit with OEM cat back as well as 3" which is why it's donut style.

Wait you paid for a 2.5" aftermarket catback? Please tell me you replaced stock with that because it rusted.
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Haha nono, the magnaflow catback came with my donor car. Its a little rusty but i dont feel like spending an other 1.5k on a 3" catback so ill run it till it leaks. I ordered a 3" cpe downpipe. I believe they supply a 3" gasket which won't fit the 2.5" catback i have. I measured the gasket that was stuck on the catback and its about 2.6" so a 2.5" gasket. I just cant find the dam part number for it. Can i just get a universal 2.5" gasket and call it a day?

Awafrican said:
The donut style gasket that it comes with should fit with OEM cat back as well as 3" which is why it's donut style.

Wait you paid for a 2.5" aftermarket catback? Please tell me you replaced stock with that because it rusted.
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I thought CPE supplied the ring type with the two bolts holes on the sides not the donut style?
 
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Hmm maybe, I bought mine used with no hardware, it's hooked to stock CBE but that was 6 years ago.. The rpm store lists the OEM donut as a optional add-on for the CPE DP so that should be all that's needed. Pretty sure I reused the stocker (car only had 30k km on it)
 
Awafrican said:
Hmm maybe, I bought mine used with no hardware, it's hooked to stock CBE but that was 6 years ago.. The rpm store lists the OEM donut as a optional add-on for the CPE DP so that should be all that's needed. Pretty sure I reused the stocker (car only had 30k km on it)
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Does the donut go into the CBE or the downpipe?
 
i have the 2.5" magnaflow cat back with a 3" CPE downpipe. the catback was on the car when i bought it. i added the downpipe. i bought a gasket from NAPA that worked if i elongated one bolt hole. walker #31574
 
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Chris' Garage said:
i have the 2.5" magnaflow cat back with a 3" CPE downpipe. the catback was on the car when i bought it. i added the downpipe. i bought a gasket from NAPA that worked if i elongated one bolt hole. walker #31574
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Thanks, i got the donut gasket hoping it'll work. If not ill use this, looks like its available on rock auto too. How much more did you have to drill out the bolt hole?
 
i snipped away about a 1/4" on both holes of the gasket. if you line it up on the downpipe you'll get a good visual of what needs to be done.
 
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For anyone who ends up on this thread for the same reason i did, CPE ships off their downpipes with a 2.5" flange gasket to hook up on stock or magniflow catbacks so there's no need to buy an extra one. One thing i did was ask them for one, not sure of they ship it by default but it doesn't hurt to ask.
 
rrodriguez9921 said:
Sid did u end up using the dounat gasket or bought the flange gasket
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Flange gasket, the donut gasket only goes on the stock cat i believe. The flange gasket is needed for the MS6 CPE downpipe. Ended up coming with the downpipe
 
A little bump for a new gasket. I got a barely used Corksport race pipe (approximately 3 inch opening) for my 6 a while back and tried this gasket on the rear, going to the stock catback. I finally got around to installing it today and it's a great fit and the quality of the gasket is top notch.

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