catalitic converter

[SpeedRacer]

is it safe to take out my cat witt the stock sensors? i know i will get the engine light. I had my car taken apart the other night about to bang out the cat but then i chickened out i thought i should get more feedback so i put it all back together. What do you guys think of taking my cat out and leaving the stock sensors? what should i accpect.

[DrPimpSiR]

Speed,
I know you don't want to hear about all that tree-hugging BS surrounding hollowing out a Cat, but...
Dude you live in the land of SMOG! The State that got us all to improve on environmental issues, killed leaded fuels, and allowed Rod Roddy of the Price is Right to say to us as kids "...and California Emissions!"
I don't think 1 or 2 hp is worth using an asthma puffer just to walk from your car to the mall.
Sorry, just my 2 cents.

[02SilverSiHB]

Originally posted by SpeedRacer
is it safe to take out my cat witt the stock sensors? i know i will get the engine light. I had my car taken apart the other night about to bang out the cat but then i chickened out i thought i should get more feedback so i put it all back together. What do you guys think of taking my cat out and leaving the stock sensors? what should i accpect.
yeah, man it's just not worth it. Try looking into a carsound catalytic converter. You can get up to a 2.5" cat and get good gains. Over at www.clubsi.com in the Got Boost forum, all kinds of people are using that for their cars. The love it and it doesn't give a terrible sound and it's legal

[David K.]

The second O2 sensor (behind the cat) is there to make sure the cat is doing its job properly. I'm not sure, but if you remove the converter it seems like the resulting signal will cause the computer to alter air/fuel ratios and timing to try and get the readings back to normal. I know late model domestic cars with OBD2 systems have this prob, but there are devices on the market that "fool" the computer into thinking that the second O2 sensor is taking a correct reading. Anybody know for sure?

I know removing the cat is best for maximum gains, but when you consider that high-flow converters are so efficient anymore, plus the pain of removing and replacing for inspections, it doesn't much seem worth it to me. However I would bet that our cars could pass inspection with no cat considering their high state of tune from the factory.

[1stockEP]

I wouldnt worry about emissions, even without cats most if not all new cars will pass a smog (sniffer) test. I doubt it will still be a ULEV, but I wouldnt lose any sleep over that.

You might want to start getting the bottlenecks out of your exhaust where they start, (headers) and work your way back.

If you are set on losing the cat and want to do it cheaply, save the stock pipe/cat and have a muffler shop put an intermediate tube in. Then you can tack on a heat shield and no one will know you dont have cats. I cant emphasize enough that you must save all of the parts that come off your vehicle. One day you may want to sell it, and having everything that ever came off the vehicle is very important, especially emissions equipment.

The heat shield/phony cat will fool almost any cop, unless theyre a gearhead, and if they are they probably wont give a hoot.

[1stockEP]

I dont know a damn thing about the sensors or what the factory computer will do if it "sees" this. I guess we are going to be the guinea pigs with this new motor.

[David K.]

Originally posted by 1stockEP
.

If you are set on losing the cat and want to do it cheaply, save the stock pipe/cat and have a muffler shop put an intermediate tube in.


It's EXTREMELY difficult to find a shop that will do this kind of work. The penalties are soooo severy, like a $25,000 fine for the shop and around $5,000 to the mechanic who does the work. Most shops won't even put your car up on their lift if you have removed your cat. Eventually someone will be producing an off-road pipe that should just bolt in. Or you could measure the legnth of your cat carefully and have a shop just make you a piece of tube that will fit in there; just don't let on what it's for.

[SpeedRacer]

yea but the cat is one pipe and it goes all the way to the header so you would need someone to cut it out then weld or create a bolt to put it back on without the cat. I want to do this but im scared that the cars sensors will mess stuff up. is thare any way to turn of the check engine light if you remove the sensors?

[00sir]

You see my post about 02 sensors, their is some boxes that allow you to fool the obd2+ cars into thinking the 02 sensor is still working.

The real question is, will it work on our 2k2 cars??? Also, is the Cat really a bottleneck in our system.. I know by putting a straight pipe instead of using the resonator free's up about
3 to 4 horses. I bet the cat gets you another 2 to 3 maybe... who knows, maybe more. I personally am leaving the stock muffler on. Keeps it a bit quiet.

On response to the environment issue...
I don't know all the facts about pollution, but I do know that new cars run much cleaner than older ones. I bet if you took your cats off, you still run cleaner than 60 percent of the other cars on road. But, I do agree, any little bit helps to keep the air cleaner. I know texas uses the excuse to lower speed limits, since we cause so much more pollution at 70 than at 55 mph. It is plow to write more speeding tickets (taxes).
I call it, speeding tax. Anyways...

Sorry for ranting,

Steve (SIR)
2k2 NHB2k2
15" Konig Helium rims/falken azenis