I used CAPS and the PNC lookup but still couldn't come with a size. I'm gutting my cat this weekend and putting my new exhaust on, and I'm pretty sure I'll need new bolts for the catalytic converter. Does anyone know their size or if they're the same as the other exhaust bolts?

they don't thread into anything. You can use any bolt w/ washers/nuts you want as long as it goes through both the cat and exhaust.

I believe they are 14mm. Get two bolts, four washers, and two nuts.

Originally posted by CODE4
I believe they are 14mm. Get two bolts, four washers, and two nuts.

that's the head size, not the bolt size. a 14mm bolt would be as big around as your finger (for an average hand size)

IIRC they're a 10mm by 1.25 thread

Neg, If I remember correctly you use a 17mm socket/wrench on those. At least I did on mine. The OEM cat has studs fitted in the flange. If I could jack it up now I could check but 10mm seems a bit small.

Either way, there is only one way to verify.

I forget the size when I did mine but I just took it to Ace Hardware and got the biggest grade 8 I could put in it.

Originally posted by CODE4
Either way, there is only one way to verify.

got yah on that one

:owned sorry had to do it

Well we were both wrong. whoops.

Turns out I didn't even need to use new bolts. The stock cat has a threaded flange on the dp side, as mentioned above, and the bolts were still good to be reused. On the other side, it has studs and you use nuts to attach the catback exhaust. The studs were way too big to fit through the SRS (ebay) 3" exhaust flange, so I had to drill them out.. big pain in the ass!!! Finally got them on.. very very snug fit though. And the fitment of the rest of the system was a PITA. But it's all bolted up, no exhaust leaks, sounds great too. I gutted the cat and there is no CEL, lol. So I didn't bother with non-foulers on the O2 to avoid the CEL.

Now I'm just waiting on the dp + exhaust manifold and my oil lines and the turbo install will begin.

Originally posted by Mike431635
The studs were way too big to fit through the SRS (ebay) 3" exhaust flange, so I had to drill them out.. big pain in the ass!!!

Stock cat studs not fitting a 3" catback? Hmm...

Originally posted by Mike431635
Finally got them on.. very very snug fit though. And the fitment of the rest of the system was a PITA. But it's all bolted up, no exhaust leaks, sounds great too. I gutted the cat and there is no CEL, lol. So I didn't bother with non-foulers on the O2 to avoid the CEL.

Ebay for you. And a gutted car is actually worse for performance due ot flow. CEL will pop up eventually.

Gutted cat's bad for performance, yes, but much better than a clogged cat. Mine was all melted and burned up inside.

Ahh yes. Definitely better than a clogged one. Test pipe for $20 bro. Always a good solution.

Yeah, I'm gonna get a 16.5" long section of 3" steel, a couple 3" flanges, and make one when I get the downpipe. I figure if the welds are ugly, only me and God will know about it lol