4 Stock Cats vs. 2
Thread Starter
Racer
Joined: Jun 2007
Posts: 299
Likes: 2
From: John's Creek Georgia
4 Stock Cats vs. 2
I have an 02 coupe with factory exhaust. I just bought the full exhaust from a ZO6. The TI part was the main reason and the rest is just a perk. My car has the 4 cat setup and the ZO6 has only the 2 cats. Is it worth changing from the 4 cat to 2 cat setup? I plan on a blower soon and that is what prompted the change as the performance for now will probably be nothing. If the pups do cause enough resistance to change, what do I need to do with the front set of sensors? Thanks in advance for your input!
Burning Brakes
Joined: Oct 2004
Posts: 931
Likes: 35
From: Rowlett, Texas
Info here suggests the PUPs cost about 5 HP.
Also, the Ti mufflers will sound a bit better without them.
Are the front O2 sensors upstream or downstream of the Pups?
I don't have them, but I think they would be definitely upstream, just below the manifolds.
In that case, no changes required to anything, the computer will easily adjust to the minor flow improvement of the Z06 midpipe and mufflers.
The rear O2's (downstream berind the cats) only serve as a sensor to tell if the cats are changing the O2 content of the exhaust - as long as a reasonably effective cat, either c5 or z06, is in there, these sensors will see a bit of difference from the fronts, and be fine. Removing Pups will not appreciably affect them.
So, do it, no downside at all.
DG
Also, the Ti mufflers will sound a bit better without them.
Are the front O2 sensors upstream or downstream of the Pups?
I don't have them, but I think they would be definitely upstream, just below the manifolds.
In that case, no changes required to anything, the computer will easily adjust to the minor flow improvement of the Z06 midpipe and mufflers.
The rear O2's (downstream berind the cats) only serve as a sensor to tell if the cats are changing the O2 content of the exhaust - as long as a reasonably effective cat, either c5 or z06, is in there, these sensors will see a bit of difference from the fronts, and be fine. Removing Pups will not appreciably affect them.
So, do it, no downside at all.
DG
Thread Starter
Racer
Joined: Jun 2007
Posts: 299
Likes: 2
From: John's Creek Georgia
What's the best idea of what to do with the O2 sensors before the cats? Should I get the new ZO6 2 cat pipe changed to hold them before the cats? Can I just disconnect them without throwing a code?
Original Founding Member!
Joined: Jul 1999
Posts: 9,037
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From: Granby, MA
Cruise-In 1, 3, 9. 10 & 11 Veteran
ummmmmmmmm
I have an 02 coupe with factory exhaust. I just bought the full exhaust from a ZO6. The TI part was the main reason and the rest is just a perk. My car has the 4 cat setup and the ZO6 has only the 2 cats. Is it worth changing from the 4 cat to 2 cat setup? I plan on a blower soon and that is what prompted the change as the performance for now will probably be nothing. If the pups do cause enough resistance to change, what do I need to do with the front set of sensors? Thanks in advance for your input!
Team Owner
Joined: Apr 2001
Posts: 54,204
Likes: 180
From: S.W. Ohio. . . . . . NRA Life Member
Original Founding Member!
Joined: Jul 1999
Posts: 9,037
Likes: 88
From: Granby, MA
Cruise-In 1, 3, 9. 10 & 11 Veteran
ok
so what do guys going to headers do? Do we just use the 2 main cats and forget the lil pups?
Safety Car
Joined: Jul 2001
Posts: 4,661
Likes: 67
From: Ocean Springs MS
Most people going with headers use one of the better systems, like LG, Kooks, or Dynatech, which come as a complete system from cylinder head to the Cat-back connection, with either off-road pipes or hi-flow cats, and an X-pipe. The factory cats end up on the trash heap.
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Original Founding Member!
Joined: Jul 1999
Posts: 9,037
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From: Granby, MA
Cruise-In 1, 3, 9. 10 & 11 Veteran
Most people going with headers use one of the better systems, like LG, Kooks, or Dynatech, which come as a complete system from cylinder head to the Cat-back connection, with either off-road pipes or hi-flow cats, and an X-pipe. The factory cats end up on the trash heap.