I need help removing my cats because I want to hollow them out. Is there any way I can remove them without having to cut the exhaust piping? Please help!

^^^^^^^

So you want to foul the air that others breathe and you are asking for help do do so?

Try the EPA

Telcoman

This is a bad for several reasons, it's illegal and your car could be confiscated for doing so and you're messing with the air we all breathe. How are you going to pass your inspection to renew your license? Now you've destroyed your cats and need them replaced they sell for $500 +/- each? I suggest you buy high flow cats, check your state laws before doing so...Gary

Epic first post. Why not try a pair of high flow cats. with any luck you can sell your oem ones for enough to cover the cost.

I can really sell my cats for that much?

Not a chance, that's how much they cost new.

I doubt anyone would buy used cats for 500 bucks. But, you might be able to get a couple hundred bucks selling them to a recycling place.

If you want hollowed cats, why not just buy test pipes and save the cats for inspections? And you should be able to hit the bolts with an air impact, after letting the nuts sit in PB Blaster, and they will come right out. Took me under 2 hours to put my test pipes in. Had to go buy a long *** extension, but the air gun set on 110psi did the trick.

How much do they run, generally?

Gun I used said max is 80. I said screw it and knocked them out with 110. Most of the header to cat bolts came out with the stud, the nut was "welded" to the stud.

Just realized that you probably asked about how much test pipes cost lol. You can find z1 test pipes used for like $120, and megan racing has new ones for like $150.

14 mm socket
Extensions of various lengths
Breaker bar
Wd40
Took me 2 hrs when I replaced mine with resonated test pipes. I really ddnt need wd40 because they came off easily one I broke the nut loose. Maybe because I live in Baton Rouge though.

Also I jacked up the car and put it on jack stands. Removed the wheels and inner splash shield which made it so much easier to see and maneuver my hands around.

I'm doing my cat now. First 2 bolts on passengers top and bottom, just need about 2 feet of extensions and 2 u joints help. Initial force with breaker and rest with impact. Was not as bad as i thought. The top is 14mm and bottom 13mm. You need long sockets. I sprayed penetrant yesterday and working today. Just needs some patience and thought. Attached socket and feed ext. up from bottom. Now the third bolt pointing down or back is next. Hoping to feed socket and ext. from back.
All this to change out the drive shaft and major pita. Also have to patch transfer case with liquid metal. What i thought was a cv joint replacement turned into a lot of extra on my 04 g35x. Gotta love your car to do all this.

I hate working on the Cats. I had to adjust mine yesterday because the Y-pipe was touching the cabin after installing the exhaust. It's a notch and a half to work on.