Having an insane amount of difficulty trying to get these things off. Following the DIY here to no success. Been blasting with PB Blaster and have even heated it up with a torch. Won't budge. Any tips?

 

Holy **** that looks like a nice little rust-weld. Might be out of luck except for grabbing a breaker bar and cracking them right off. Do you park in sewer water infested grass or something?

 

guess 92,000 miles will do that

 

DON'T try to take the bolt out, undo the NUT.

The bolt is splined into the body of the cat.

 

The bolt is tac-welded to the side of the cat. I used a dremel and grinded it off, then took a punch and drove the bolt out, but to do this I had to completely remove my Cat off of my exhaust manifold.

 

Does anyone know the specifics of the bolt and nut, so I can just get a new one to replace them?

 

+1 to what stealth said. have someone hold a wrench on the nut, and get down and try to kick that sucker off.

you can get a new oem bolt from mazdatrix, or just get something that works from home depot

for warranty purposes though you should probably stick with oem hardware...

 

^^^ Not that they would notice hehe

 

So i take it the cat made it?

 

remove the NUT. not the bolt.

if u can't get a grinder and grind the bolt head off.

road salt is magic, my Autoexe adjustable end link rust with just 1 winter.

 

Yeah, it made it here fine. Now just trying to get it on. Thanks for the quick response and shipping.


I was able to get the front nuts off. Used a breaker bar and a hollow pipe as an extension, actually came off relatively easy as compared to before. Used a lot of PB blaster and actually heated it up with a torch, too.



Now stuck on the rear ones.

 

Okay, so I just installed it. I bought it from Nnu77howz3 who had it on a 2006 with around 38,000 miles or so on it. Mine is a 2004, but from the dumb question thread apparently since they're both Series I it should work.

It definitely sounds louder. Especially under 3-4k RPM or so. Drove it around the block and there's no doubt in my mind that it is louder than normal. Also, when I put it in the garage there was definitely some smoke you could smell and faintly see in the air. Any ideas now?

 

Okay, it's louder as I accelerate and advance RPMs. I smell burning when it's in the garage. Unless I was sold a bad cat, or the 2006 version is not meant to go on the 2004, I'm not sure what's going on.

 

You might have an exhaust leak. Did you replace the crush seal between the cat and manifold? Was the rear donut gasket in good shape? Is everything tight? If you used pb-blast or something on the nuts and bolts, it could be burning off causing your smell. A bad cat would smell like rotten eggs a bit. An exhaust leak will smell like exhaust and unburnt fuel depending on where it's leaking.

 

put your hand NEAR, not on the seams of the flanges and try to feel if there is a leak. You should not feel any hot air coming through either side of the mid pipe.

 

Problem solved. Forgot to take that o-ring thing off towards the rear part of the cat from my old one and put it onto the new one. So there was a leak, thus the loud noise and smell of burning fuel. Thanks for everyone's help.

 

np buddy

 

Glad you found the problem.

 

that was a dangerous problem.... (I can see the op slowly getting more and more tired as he drives to work)