I recently overheard a guy mention that, in order to deal with some problems he was having with his catalytic converter, he simply cut open his exhaust pipes and converted to what he called "straight pipes," i.e., avoiding the muffler, etc.
Assuming you live in an area which does not require emissions inspections, which is the case for me, that sounds kinda appealing. What are the advantages/disadvantages I should know about before doing this?
Even though you don't have emissions inspections, I believe its still illegal to drive around with no cats...for obvious reasons. The cats are there to neutralize harmful byproducts of the combustion process so by removing them you are spewing much higher levels of toxic particles into the evnironment.
Now, if you were to remove them, you might gain a few horsepower but you'll also lose some low end torque due to the decreased back pressure that the cat used to provide. In a car this isn't a bad tradeoff, but in an off-road vehicle I think I would want as much torque as possible. It'll also make the vehicle much louder, although this may or may not be a deciding factor for you.
He just ran a straight chunk of pipe across the space where the cat used to be. Maybe same for the muffler to check for blockage too.
My 86 CJ7 comes stock with a real 'straight pipe' and muffler at the rear setup. It doesn't need a cat up here in Canada for emissions. I still pass emissions too.
The newer Jeeps have the pipe running all over creation so they could fit a Cat in there so just putting a chunk of straight pipe in isn't really a 'straight pipe' exhaust.
You can't run 'open' pipes for long. Straight or bent, you need a muffler on there to give some back pressure. Your valves are designed to need some resistance in the exhaust.
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's" snipped-for-privacy@msn.com" wrote:
Straight pipes are louder than hell and I almost gurantee you'll get a ticket for that. Next if you do a lot of forest wheelin you'll no longer have a "spark arrester", as your muffler acts as one. I just installed 3" cats and 2-1/2" tube mufflers in my Grand Wagoneer and it runs better than ever.
Mr. Bill at a 4 way stop.....the vehicle with the largest wheels has the right of way My Jeep is not an SUV....your SUV is not a Jeep
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