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Hey guys,
I live in an area where emissions aren't an issue. Getting new headers for my 80 302 and hopefully a cat back system if I can find one or have one built reasonably. I don't know much about catalytic converters, was wondering what the pros and cons would be to removing it vs. keeping it. Thanks
There aren't to many pros as for leaving the catalytic converters on a vehicle. They do create a little back pressure and convert some of the more hazardous emissions, but that is pretty much it. I would recommend either taking them completely off, which most shops won't do because it is illegal, or replacing them with high flow cats. High Flow cats are the best alternative because you still would have the cats on your truck but it would hamper your exhaust pressure that much, giving your engine the breathing room it needs.
If your truck is a 1980 model with typical miles for that vintage and it still runs good with the cat, keep it! If the truck came with a cat, it should still have one even when the truck turns 25 years old. I went with high flow cats, but, that fact is only because my truck is a 1982 and is subject to regulation. I welded and pieced my exhaust system from a cat back kit from Summit. I added the high flow cats and good quality mufflers. You can buy all the parts you need to build a complete exhaust system with or without cats. In most cases, you don't even need to weld it together if you don't have a mig welder. Just be sure to buy slip joint pipe and plan your job first from the catalog. It sounds like a big job but really is not. Yes, it does take some time on your back if you don't have a lift, but set your pipe, support it and you will be surprised at how fast everything goes together.
They don't have emissions in the area I live, so a cat isn't required. Would their be any benifits or draw backs to completely removing the cat is what i'm asking, other than increasing green hosue gas emissions.
You seem determined to remove the cat and my short answer is no. It will not hurt the perfomance of your truck in any way as long as there is no computer sniffing the exhaust. There is no significant benefit to removing the cat either. I am making the assumption that there is nothing currently wrong with the catalytic converter and your 302 runs according to original specification. You will not save any measurable amount of fuel and you will not feel any sort of performance boost, and I mean absolutely none by the seat of the pants. You may improve the sound of your exhaust, if slightly louder is better.
Last edited by 82F1507.5; Sep 16, 2004 at 04:33 PM.
New headers and true dual exhaust!
Oh, by the way I did not mention that in order to do this, you still need to run both pipes down the right (passenger) side of the truck, almost up to the rear axle. This means that you need either a single muffler with dual inlet and dual outlet, or join the two exhaust pipes at some point before the cat or before the mufflers if you omit the cat(s). There may be a few posters who will argue that it is not necessary to join the pipes, but most people who build exhaust systems, will tell you to balance the dual exhaust with a common joint.
They don't have emissions in the area I live, so a cat isn't required. Would their be any benifits or draw backs to completely removing the cat is what i'm asking, other than increasing green hosue gas emissions.
There are few benefits to take it off.
but if you are putting headers on, don't worry about it; leave that sucker off. However, make sure you can put it back to stock if need be. Emissions are coming to a town near you someday. Maybe not this year or next, but I would not be surprised if every place has emissions in 10 years..
So, if you expect to be running your truck in 10 years, make sure you remember how it was from the factory.
you would only see about 10 hp at most if you take them off, its realy not worth the trouble. But if you plan on doing a whole exhaust then it will save you some money to not put a new cat on.