95Marklll(Kingcobra)
Well-Known LVC Member
What gains will I have with removing the 2 small cats?
2 small cats
- Thread starter 95Marklll(Kingcobra)
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Dominus
Dedicated LVC Member
Not if he eliminates them with an Xcal. 
MonsterMark
Dedicated LVC Member
No much IMHO. They are fairly high-flow from the factory and matched to the engine.
95Marklll(Kingcobra)
Well-Known LVC Member
I know if I got rid of them my car sound little bit better and even if there high flowing as it is, a pipe is alot less restrictive then a high flowing cat, I would think id get better mileage and maybe 10-15 hp im guessing, idk.
gangstaMK8
Well-Known LVC Member
95Marklll(Kingcobra) said:
i dont know if u will get any gains... but u will not get a check engine light and u will not have a problem passing emissions either. As long as u keep the main cat on there or replace that one with a high flow one.
Ricksquickviii
Well-Known LVC Member
gangstaMK8 said:
You mean removing the third cat and resonator you will pass emissions, if you remove the other two cat's you will fail I believe.
gangstaMK8
Well-Known LVC Member
Ricksquickviii said:
No the "third cat" is actually the main cat at least on a 94 it is the biggest one on the car. The smaller 2 cats which are no bigger than a football can be removed. The 2 small cats on the car u cant get a aftermarket high flow cat but the main one u can.
Redwingvksm
Well-Known LVC Member
gangstaMK8 said:
You won't see any noticeable improvements. Just leave them so you don't piss away your time and money.
gangstaMK8
Well-Known LVC Member
Redwingvksm said:
You won't see any noticeable improvements. Just leave them so you don't piss away your time and money.
LMAO Thats awesome
Ricksquickviii
Well-Known LVC Member
The two cats on both exhaust manifolds leave, the third one is the by the resonator, so i would pull the resonater and the third cat next too resonator, and replace them with xx pipes!
jdlmkviii
Well-Known LVC Member
Calabrio said:
No, not for the 95's and below. The post and pre cat O2's didn't start until OBD-II (96 and up). The OBD-I's just have the pre cat O2's which only monitor quality of combustion for the air/fuel mixture
rice cooker
LVC Member
i still have all 3 of my cats on my car but no one said there was any thing in them. i punched them out and picked up a little power ill say maby 5-6 hp but i also got about 4-5 better MPG wich is a big plus running high oct fuel
Frogman
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4-5mpg by removing the cats? right.... In what dimension??
Unless the cats were severely plugged up, I doubt you got such mileage gains.
Unless the cats were severely plugged up, I doubt you got such mileage gains.
rmac694203
Dedicated LVC Member
The first cats after the manifolds are the main cats. That's why they are monitored on the 96+. If the primaries "didn't matter," it seems to me that they wouldn't have O2's before and after them to moniter them. At least that's what I have come to understand here. Either way, on pre-96 it seems that it wouldn't matter. The third cat is not monitored so it seems to me that it wouldn't matter if you remove it.
Frogman
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The rear "o2 sensors" are not really O2 sensors. Their purpose is to monitor the health of the catalyst in the catalytic converters.
If you remove the cats on an OBDII car, you will get a check engine light. Ofcourse, that can be turned off with a tuner, or a module (well, two of them) that will plug into the Rear sensor plug harness, and will fool the computer into thinking the cats are still there.
The modules can be had from Caspers electronics. Or was it Casper electronics. Either way, there are options if you remove the main cats.
If you remove the cats on an OBDII car, you will get a check engine light. Ofcourse, that can be turned off with a tuner, or a module (well, two of them) that will plug into the Rear sensor plug harness, and will fool the computer into thinking the cats are still there.
The modules can be had from Caspers electronics. Or was it Casper electronics. Either way, there are options if you remove the main cats.
rmac694203
Dedicated LVC Member
I got some MIL elminators a while back when I was planning on gutting my cats but never really got around to it. I don't really know how or if they work but I got them for next to nothing so I figured what the hey.
turborich
Dedicated LVC Member
The two small cats are called "warm up cats" They are right near the exhaust manifolds so that they will easily become hot shortly after starting the engine, they then cause the main cat to become hotter faster. This allows the emissions to be within goverment standards much faster. If I were you I would leave them in place. You will not see much if any gains by removing them.