If you take out your cats will how that effect gas mileage?

Question

If you take out your cats will how that effect gas mileage?

Answer 1

Regular sized automobiles mpg generally is effected plus/minus 300 lbs.  Usually weights less than that does not effect the mpg enough to notice.   So when people head to the gas station more often to thinking they save gas by not "carrying" a larger load in their tanks - they're actually wasting more fuel by making more frequent trips to the gas station.

Answer 2

does not affect until the cats weigh like 100lbs

Answer 3

Do not remove your catalytic converter.  It is a complete urban myth that cars run "better" without "all that emissions c**p."

Maybe this was true in the early years but today's vehicles are so integrated with the pollution control devices that you are in for a world of hurt if you get all macho about the cat.  Your car will run crappy and you'll drastically reduce the life expectancy.

Plus removing the Cat is irresponsible to the rest of us who have to breathe over 200 different types of toxins produced by your unfiltered engine.  Don't be that jerk.

Also - I do believe it is a federal offense to tamper with, remove, etc. a catalytic converter.  You won't go to jail but you wont be passing any vehicle inspection soon.

Answer 4

depends on the car...

on my 67 pontiac, straight pipes increased flow, reduced back pressure, and increased horsepower (she was running rich before anyway)

usually just removing the catalytic converter will reduce backpressure, and in doing so will make your engine run leaner...if your engine was running rich to begin with, this improves the situation, if it's running at proper mix, or a little lean already, it will not help...