I just took my cat off and made it a straight pipe today. The air pump is just kind of hanging there. My questions are...

1. Will just leaving it hang there later provide an error code?

2. Is there an easy way to program the engine to stop using it?

3. Am I able to hear it pumping air? (if not... Theres a hole somewhere in that straight pipe. LOL)

it will make noise and all you have to do is plugit but you may get an error code not sure which one someone else will know you should probobly just have it welded to the straight pipe like the way the cat was it just pumps exhaust air

I might just leave it there. Doesn't look like its harming anything.

Need to bump this. Not the exact answer I was looking for.

Although I have a magnaflow hi flow cat, the exhaust shop never hooked it up on my car..they welded the O2 thing shut. I guess they assumed I was installing the cat just for visual inspections ?

Anyway, I have'nt got a SES code or anything related to that. I can definately smell the unburnt fuel though.

Also, can anyone answer this: would not having the cat hooked up result in lower gas mileage? I've been getting about 18 MPG lately and although I haven't really been on the highway that seems kinda low for a 305TPI with 2.73s.

JUST CUT THE BELT AT THE AIR PUMP- i have done this when i first fot my z and i have never had any trouble, i am getting ready to install my cat eliminator pipe - curious how different yours sounds without the cat - any noticable extra power?

i love the smell of no cat, its great....... i never get any codes except the EGR code, but than again i got a block off plate on my EGR


BTW Nice look with the old school wheels

I take my cat out after emission's testing and just plug up the air pipe with some rubber pipe and bolt(keeps all the crap out of it so you can use it when going for testing next time) then tie it to frame out of the way.Never had any codes,the car runs fine and sounds louder

The only thing the computer looks for is the EGR. However, you are violating federal emissions laws by removing it, and you're telling our lawmakers that the current punishments for violating the laws are not tough enough to stop you. Eventually they'll make more laws and take away everyone's fun.

Please be a responsible hot rodder. Keep your car emissions legal and do us all a favor.

1. To the person who asked if there is extra power.

The answer is YES. My catalytic converter was severely killing my sound. I can notice a bit more power. Just a bit. If your going to do it, do it for the sound or if your really trying to get all the horsepower you can. But the fact is you can put an airfoil in your throttle body to get you more horsepower than taking the cat off will. You make the decision. Mine honestly sounds like a race car now. It's not louder than a few of my friends cars... (02 Camaro SS, 02 Mustang GT, and 00 Trans Am) but now... its SUPER close. You make the choice.

2. I'll just unplug it if an error code comes up. Find something else to do to it.

Thanks guys.

Well the LS1 guys usually like to use those nice y-pipes that connect longtubes to a catback, and those usually delete all their cats. Just some O2 simulators, and they can pass emissions too!

There's no way an LS1 with no cats will pass a visual inspection during their emissions test, so something sneaky is going on there.

Aw here in my town the emissions techs are so lazy, they dont even look under the car. I brought my last car there 3 times before it passed, and I finally I asked the guy if he saw what I did to get it to pass (welded a 2nd cat behind the 1st one). He said he never looked under the car at all.

But on the newer cars, they just plug it in. When I used to work at firestone, they just plugged them in. Too much wasted time crawling around on the floor.

lol

if you gained power from ditching your cat its because your cat was clogged, which is very common, a high flow cat, while costing you 200+ dollars wont cost you any power and keeps you emission legal.

As for the air pump, while this wont keep you emissions legal, just ditch the whole thing. Ya you wont pass a visual but that thing is the stupidest piece of junk they ever put on cars, and does virtually nothing.

All you do is delete the pulley completly by unbolting the whole system, and run a shorter belt. Theres a tech article on the main page as to the right length belt to use.

https://www.thirdgen.org/serpentine

it keeps the catalytic converter at optimum operating temperature. which lengthens the service life of the converter itself and helps keeps the emissions down.

maybe it helps the life of the converter, and its SUPPOSED to help keep emissions down, but enough people have deleted it and passed the sniffer anyways so it clearly doesnt do all too much to help the emissions. Hence it being a 20lb piece of junk

you must have never cut open the "sand box" of a cat that GM put on cars and trucks, it might as well been clogged up, off the showroom floor

right i have no doubt about that, but what i was saying is has mostly to do during engine warm-up when catalytic converter is not doing its job because its too cold. the air pump heats it up faster. im not trying to argue, just stating that it does do "something". im with you tho on removing it, but unfortunately i can't due to being in california.

No one is debating how much stock cats suck or not. We all know stock cats are horrible and should be replaced with aftermarket "high-flow" cats as soon as possible.

As Quickstyle said, the benefits of the air pump are long term. Yes you can pass the sniffer without one, heck you can even pass a sniffer without a cat. But with a 3-way cat that requires air, you are removing a part of the process that the cat needs to do its job. Hence, it will fail sooner than it should. I believe there are cats out there you can buy that dont require air, but again, you've violating federal laws as our cars are required to keep the air pump on there.

I personally do not like the emissions from cat equpped vehicles. I read on a few sites quite a while ago about them actually being more dangerous than non-equiped emissions.

I also did not like the horrible smells emmitted from my car when the cat warmed up. It was TERRIBLE and literally made me hate to drive the car.

Meh, I'm lucky here. Illinois = no emissions testing for 95 and older

Mine will be off soon.

yea you got to love the smell that a cat equiped car makes when they are getting on it

That smell only happens on original 80's stock cats. New aftermarket cats do not emit that smell when heated.

My brand new 3 inch in/outlet Carsound cat did from the day I had it installed.

yea but stockers smell........... everytime some stock car starts playing hard you can smell it

If your cat smells from normal driving, then I would say your engine has a problem. More than likely its running lean, which is making the cat run hotter, causing the smell.

then every car in alabama must have problems, because thats all i smell when people with stock cars get on it.....well not all of them but i would say atleast 75%
....but if you ask me a cat cars have an special smell all the time you cant notice it unless is maybe running in an enclosed or simi enclosed area.....big difference that a car/truck with out a cat... i would like to know the science behind that smell, like what kinda reaction or gasses are in it to cause that smell
all they smell from me is the smell of a car with no cat

Yeah personally I prefer the smell of no cat. However, I dont like it if I have to drive behind somebody with a combination of no cat / very rich condition. Then the smell just gets annoying.

But I would be that ******* that will drive around spewing HC's into the air for all the other damn suits that block the highway every morning on the way to go work at their insurance company cubicle job all day... those type of people **** me off so much. I would tune the car rich for a few days too when I get EBL, just so they can smell the wasted gas as they b**** about the price!

Thanks for being a butthead hot rodder. What will probably happen next, is you'll be in front of some government official, and he'll see and smell your car, and how wasteful polluting it is, and go write some law to ban modifying cars like yours in your state, and then you'll be cursing and complaining like we do in California.