Easiest way to hollow out cats????
 

Local shop told me to unbolt them and use a piece of pipe or rebar and bash the brick out. Reason for doing this is their clogged and I cant rev past 4000 rpm or get over 60 mph. Put my foot on the tailpipe and the car almost dies, not enough pressure to blow foot off :mad: Anyone done this? If so whats the easiest/ least expensive way besides this>>> :Kill1:

Go straight Headers! lol

Or weld up a cat replacement pipe

Or just keep bashing it away

What they say to do works on most cars, and can be done on the pre cats but will not work on the main cat. It has some type of sheild in front of the hole and you cant get the rod into it.


Remove it and replace with a pipe.

shove a broomstick through it and then get an air compressor to blow out the remains

i think the cat is 18inchs long just goto the muffler shop and thell then you need an 18inch pipe with this end and this end on it (the ends that are on your cat) and have them weld on in the same spots on each side take it home bolt it on but smach out the pre cat 1st

the pipe can be like 2 1/4

good luck PaTricK

Well my only problem is..... During inspection or when you get stopped by a highway patrol, if they look under your car and see the shell of the cat your good to go. BUT if they see the cat replaced with a straight pipe its a $500-$1000 fine! Dont wanna risk it.

My words sparked a idea! I'll have the straight pipe made, Then cut the old cat apart and weld the housing around the straight pipe. Only as a last resort cuz I'm lazy and it sounds like too much work!!!!

fake the cat around the strait pipe?

i was gonna hollow out minr too after i got a crappy free flow one..................after i looked at it i tried some hammering but no go, all that thing is good for is restricting(main cat).....just go get a new one dude(free flow. muffler shops have them) the stock one wieghs a ton too

Its been done before, plenty of times. I have two cat converter shells waiting to go around my straight pipe

Like someone mentioned, just get a broom handle and punchout the insides of the cat. I have 2 cats. One that has lost innards and is on the car 364 days a year, and one that goes on one day a year to pass emmisions.

I like crowbars myself....but yes...definately weld or bolt the cat shielding over the pipe...the visual inspection is key!

i tried hollowing mine out at first, then said screw it and got a straight pipe from racingbeat...

What about a 12 gauge with slugs?? Bet that would blow the shit out of it!!

easiest way is a crowbar and a hammer.

Location: texas


...no comment ;)

..just go at it with a hammer and screwdriver/crowbar/rebar.... :)

Matt (so glad my 82 doesn't need to pass emissions....)

I thought all vehicles past 79 had to pass emisssions

a while ago sport compact car (i think) did some test on different sized engines 4,6,& 8 cly and they found a gutted cat is worse than the stocker because the air flow is messed up by 2 things the jagged honeycomb yoy dont knock out and the pipe expanding and contracting twice. so striaght pipe+shells is the way to go.

Hell yeah texas!!! GETRDONE!!!. OK redneck jokes asside, Thanks for the help :buttslay:

Don't worry man, I was raised in one of the most redneck/backwoods places possible.... :D ...it was just so beautiful, I couldn't pass up on it :)

Good luck with the cats!

(The secret is a really big hammer ;))

The cats lost its guts!! BUT there was only 1 cat on my car, and from looking at the exhaust i beleave someone took it to a shop and did a hack job on replacing the exhaust. I think the only factory piece is the pipe right before the muffler. It was all welded so i had to hack it off with a sawzall and the honeycomb crap fell out like charcoal briquets!!! Used a tire iron, one with the sharp flat end, and it did the trick perfectly. Got every thing out and the shops welding it all back together today. Damn it made a differece too. Car is fast as hell. My ear still rings though from the open header!! It also smothed out the rough idling. Car just couldnt breath!

I used an impact hammer.....

Be careful of the emmisions tube that goes through the back cat.

Jay
1984 FB

A cat replacement pipe really wasn't all that hard to make. I had some flanges from a couple dead monolithic convertors kicking around and some spare Racing Beat straight pipe. No need for that emissions tube anymore either.