this is for anyone from PA or anyone farmiliar with emissions testing. i live in lansdale, PA 19446. its in montgomery county, about an hour from philadelphia. i really want to redo my exhaust. i am considering getting headers and/or taking out one of the cats (the rear one). (see signature for specs) i just want to know if i do take out a cat, if i will be able to pass emissions? i know theres alot of laws that deal with "tampering" with exhaust and i just want to know how much i can get away with. any help is appriciated. thanks, john

 

It all depends on where you are, I dont have a clue about the laws where you are. But I'm lucky, i live out in the sticks and in this county there are no emissions tests, so i pretty much dont have to worry. But isnt it illegal to remove a cat no matter where you are, like a fedral regulation or something?

 

Yes. People often forget that, but it is a federal law that prohibits you from removing any factory emissions equipment unless it is replaced with something that performs equally.

 

yup, fereral law prohibits tampering with catalytic converters. (obviously some areas people never check)

what about headers and a high flow cat. I'm not sure how the 300ci are laidout but bassani has a mid-pipe with and without cats.

emissions. The main thing that is being measured is hydrocarbons, or un burnt fuel. I have heard of people passing the very basic sniffer tests in Massachusettes without any cats, but the cat is what takes care of most of the hydrocarbons if the vehicle is running rich or has a slight miss fire. The cat(s) does other things too like cut down carbon monoxide, NoX, but around new england they are checking mostly for HC.

They also go by age/year of vehicle. Meaning, the test is easier for you than it is for a 2001 vehicle. It is possible for you to pass the sniffer without a cat if you are well tuned up and they overlook the fact there isnt a cat, but its a chance to take.

If I lived where you do I'd do headers, one hi-flow cat, straight pipe the rest of the way back!

 

You probably could pass the emissions test with one cat if your truck is well tuned, but if they notice it's missing your screwed. A better idea would be to hollow it out and hope you pass but thats still illegal. Realisticaly the monolithic convertors they have been using since the 80's are capable of flowing more exhaust then the rest of your system can handle. So by removing you won't gain any more power (unless the old one was plugged up because your truck isn't running right). It would give you a slightly better exhaust sound though if you have a high flow muffler. Plus if your truck is 1996 or newer you probably have a o2 sensor behind the cat, which will turn your check engine light on and give you a catalyst inefficiency code if the cat is missing.

-Jon