I'm thinking of ordering dynomax direct fit cat..just wondering how long and how hard it was to take the old cat out and put the new one in? also will this give me some sound ? and will I notice a power gain?

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1988 Sport Coupe 305 TBI
K&N
Flowmaster exhaust


Daily driver:
1988 K1500 5.7 4x4 shortbed flowmaster cat-back gutted cat.
AOL: RyanNH84

 

My stock cat was clogged, so I got the Catco one from Summit Racing's web site. It made the car a little louder with a deeper tone and made a pretty decent power increase. I had to cut my old AIR tube to get the old cat off, but other than that, it was a painless job that took me less than an hour to do. But I did have to take the car to a muffler shop and have a new AIR tube welded on.

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1987 Chevy Camaro IROC-Z
L98 TPI 350 (5.7L)
TH 700R-4 Transmission
Borg Warner 7.75" 9 Bolt Rear End with 2.77:1 Gears.

Current Mods: LT4 HOT Cam, Comp Cams 1.52:1 Roller Rocker Arms, Accel High Flow TPI Baseplate, Edelbrock TES 1 5/8" Headers, Catco 3" High-Flow Catalytic Converter, Hooker 3" Aerochamber Cat-Back System, Transgo Shift Kit, Performance Resource Chip, Accel Ignition, K&N Filters, Jet TPI Air Foil, All Free Mods, Falken ZIEX Z-Rated Tires.

Best ET: 14.32 @ 97.7mph
(corrected for elevation)

 

You don't have to weld the air tube on. A repair kit is available that has a high-temp rubber hose in it to connect the cut-off tube to the new cat's tube. Just cut the old one off at about the same length as the new cat's tube. Makes the next replacement easier, too.

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82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R4. 2.93 limited slip. Cat-back from '91 GTA, ZZ3 intake, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LG4 w/'87 LB9 block, ZZ3 cam, ported World 305 heads, Hooker headers & y-pipe, 3" Catco cat & 3" cat-back, Spohn SFCs).
57 Bel Air, my 1st car. '66 396, 9.7 CR forged TRWs, Weiand Action+, Edelbrock 1901 Q-Jet (Holley 3310 on the way), GK 270 cam, Magnum rockers, Jacobs Omnipack, 1-3/4" Hedders & 3" Warlocks, TH400 w/TCI Sat Night Special conv & Trans-Scat shift kit, MegaShifter, 3.08 8.2" 10-bolt w/Powertrax, AMSOIL syn lubes bumper-to-bumper. Idles smooth @ 600 RPM in D. Best 15.02/95.06 @ 5800' Bandimere (corrected 13.93/102.4 @ sea level).

 

I just took my y-pipe off with the cat connected(was already 3") and had a shop cut the cat off and enlarge the end so I could slide my new y-pipe in. An hour later under the car and my edelbrock y-pipe and the cat were bolted in. I used fuel injection line to clamp down on the air tubing, its pretty strong stuff.

 

What did you guys use to cut the air tubing??

Mine is welded on as well and I was wondering why that sucker wasn't coming off!
It has welds and a little screw down clamp. Guess they REALLY wanted that air tube to stay put.

Any where can I get this tubing to secure the new tubing when I put on the new cat. What do I ask for at the auto parts store??

And I'm not exactly sure about this yet, but......
I think I'm going to run into a problem where the cat meets the y-pipe. After taking off the clamp there I noticed the ring indention that the clamp left. Is this gonna be able to be removed from the y-pipe with a BIG hammer?

Any thoughts.....

 

I used a pneumatic cut-off wheel. It also comes in handy when dealing with that clamp-dimpled pipe - just cut the top layer in a few places, it will come off.

Ask for an air injection repair kit at the parts store.