catalyst that converts bad chemicals in the exhaust into harmless chemicals. Try www.howstuffworks.com I'm sure they have a writeup on it.
Ok i read it, thanks But does it have anything to do with performance? Would the car perform better if it has it or if it didnt? Thanks again!
I would assume that anything that is inbetween air coming in or air going out is going to reduce performance. o No:
It really depends on the pipe sizing, whether you have an aftermarket catalytic converter, and a few other things. I'd say that if you had a full 3'' system and one of those aftermarket cats that are designed for "performance", you'd only lose a couple of hp than without one. If you have the stock one, what are you waiting for? Cut that thing off already! If you don't have emission testing in your area, just cut it out and stick a straight pipe in there (or you can be sneaky, take the cat out, cut it open, gut it and stick a straight pipe in it and then put it back up there).
My brother has a '76 LTD Wagon and he wanted to take it off, but wanted to make sure before he did. And since it's a '76 next year it wont need a smog check (i live in Cali) Thanks guys :TU:
Marvin, The main job of the catalytic converter is to convert hydrocarbons and oxygen in the exhaust to carbon dioxide and water. The catalyst in the converter is platinum, or palladium, I believe. Catalytic converters are usually somewhat restrictive, and generally increase back pressure and hurt performance. The catalyst is not compatible with lead, it will clog the converter. If you remove the converter, you can use race gas in the motor.
man and you guys complain about emissions. everything newer than 1968 in WI has to get emission checked. though.. if you put "collector, hobbiest" plates on it you only need to get emission tested one time. (i had to do it today infact) nate
FYI, cat converter cores are worth a few $$. Try to find someone who recycles them. In theory it is against the law to take them off. If you need to pass emissions you will probably need it. 1966 and newer get tested in AZ. John
May be more to it.... Many states that do not have an exhaust sniff test for a given year still have a visual inspection to make sure no such equipment has been removed. If it has been removed it will not pass inspection until the removed equipment has been reinstalled. So I would be careful to understand your state requirement before I took out my sawsall.
A well tuned car should be able to pass without one. Though lots of people look like they have one, in reality they don't. No one check them up that far and lots of guy just jam a piece of pipe down the center of it, so it looks like a cat, but flows like a pipe.
yea my buddie is getting hosed though because he has an aftermarket air box on his air cleaner. (he has an AWD eclipse) he has cats, they dont have a dyno around here for AWD so it's visual only. it would pass no problem if it wern't for the visual. I've heard of people having hollow cats and the inspector taps on them with something to verify that the catalist is actually in there. this just forces people to use the remote controlled bypasses.
cats are very restrictive. if youve ever taken a look inside one youll see what i mean. its like a honecomb inside. there are thousands of little holes or tunnels that are about the size of a BB. this is what your monstor has to breathe through. there you have your trick flowing headers and your 5 angle valve job, your exhaust port bored out, your CAD designed collectors and your 3" exhaust...then WHAM!! all tha is forced through about a foot or so of ceramic honeycomb. talk about an increase in backpressure and a decrease of EGV! im not sure how much power youd get by removing them...but beware, tampering with a working cat is an offense on a federal level. but then again, when it comes to emissions, it all depends on who your dealing with...and who you know. if you dont have to have the sniffer, and your station isnt that picky and usually dosent look for a missing cat...then you might get away with it. or like somoene else suggested, knock out the kitty, and put a pipe running through the center for those stations that look, but dont smog. or you could go other routs like a new exhaust system with straight pipes (no cat), or like many people in the import world do...and that is bolt in a "test pipe". all it is is a peice of stock diamater piping with flanges on both ends to bolt up in place of the cat. easily swapped for inspection and whatnot.
I'm not normally a stick in the mud, but.... cats really do the job they are supposed to do. You can do everyone a favor and retain your original equipment converter for on road use... they are not very expensive. http://www.google.com/search?sourceid=navclient&ie=UTF-8&q=high+flow+catalytic+converter Frank
One more car isn't going to make a difference, if the gov really cared about emissions they'd go after the big factories that are continuously pumping out black smoke. If someone is *really* concerned about the enviroment, don't keep the stock cat, go buy an aftermarket one that flows better and does the same job. :TU:
One might not, but 0ne + one + ... WILL. It's kind of like pouring your old oil down the storm sewer. If you were the only one who did it, it prolly wouldn't make too big of a difference. It's still a bad idea. I don't understand your second point... stock cats work fine, but restrict power. Aftermarket units aren't cleaner, just more performance oriented. Right? Frank
Even with the 1+1+etc, it still doesn't compare to the big factories. If you've ever lived by one of these solid-black-smoke-pouring-out-of-8-stacks-24/7/365 factories, you'd know what I was talking about. Part 2: Yes, I said they do the same job as the stock ones but flow alot better so there's less loss of power. http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=1292&prmenbr=361 http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=192834&prmenbr=361
The aftermarket cats are more flow so performance oriented as far as more flow is concerned. Not all outflow the stock set up by much in the modern performance cars. I know on my 96 Z28 the stock y pipe which has dual cats flows pretty well on all comparisons I've seen with Random Technology, Bassani, Catco and Dynomax aftermarket units. There are plenty of folk in the F-body community with 93-97 LT 1's and 98 -02 LS 1's that keep stock cats gutted with a straight pipe through and can still pass emiissions running clean with a good tuneup and warmup prior to testing. These are on mild bolt on modifications. It seems once you start reprogramming PCM and removing emmissions AIR and EGR while adding headers the O2 sensors can be problematic. The stock units also last longer since the materials used in them are different than aftermarket as far as casing and internals are concerned. Changing the cat location or alteration is a federal offense so you better know your shop you're having do the inspection if this is the case. Some shops around me won't even do a cutout if they don't know you.
