Can I cut the cats off my 2000 chevy 5.3

Discussion in 'Chevy Truck Talk & GM News' started by Outlaw19, Feb 9, 2014.

  1. Outlaw19

    Outlaw19 Member

    What is everyone's thoughts on cutting the cats off my 2000 chevy Silverado. I have dual exhaust with no mufflers but it isn't as loud as I would like it. Will cutting the cats off do any harm?
  2. Scott_Anderson

    Scott_Anderson Rockstar 100 Posts

    Till the day comes you have to have a MOT inspection.

    If I'm not mistaken there are exhaust sensors before and after the cats to control the fuel mixture for emissions purposes.
  3. Outlaw19

    Outlaw19 Member

    I have farm plates and don't need to e test. Has anyone done this with a 5.3l if so what do you do with the o2 sensors.
  4. zuki82

    zuki82 Member 1 Year 100 Posts

    As I sit here with a constant ringing in my ears from years of loud exhausts and gun fire, and music, I gotta ask, why do you need to go louder? The cats don't stop that much noise, your not gonna gain any noticeable decibels with out them unless they are plugged! Just run a rod thru them if you really want to open them up!
  5. Pikey

    Pikey Moderator Staff Member 5+ Years ROTM Winner 5000 Posts

    you will have to get an O2 replicator so you don't get a service engine light and decreased mpg. I have seen them on the web. I have also heard of guys buying spark plug non foulers from the parts store, cutting the cage off the sensor, screwing 2 non foulers into the hole in the exhaust where the o2 sensor was located and then screwing the o2 sensor into the non fouler. The idea is to get the o2 sensor out of the exhaust stream so it has a different reading then the front o2 sensor. I know guys that have done it on dodge rams with a hemi, don't know anyone with a chevy that has done it.
  6. WorthFlorida

    WorthFlorida Rockstar 4 Years 100 Posts

    Where's the beef? With computer controlled everything, the 02 sensor helps the system to adjust the fuel mixture, timing and who knows what else. Removing them will only let you burn more fuel, probably less power, maybe even cause engine knock. The knock sensor will then cause the timing to retard even more and your engine will run more inefficient. Back in the the 1970's when cats first came out, they were like dragging a safe behind the car and with limited computer controlled engines, everyone want those things off, AND every car and truck had engine knock. If you never heard it you swear there was a can of marbles in the engine. Today, the engines run better than ever(even in year 2000), absolutely no knock and burn less fuel, so why do you want to pollute the air even more?
  7. Char

    Char New Member

    If you have the money look into high flow cats. Not sure how they sound with no muffler but it will allow more unrestricted air and that seems to be what your going for
  8. Dana W

    Dana W Rockstar 3 Years 500 Posts

    The computer will go to rich mixture, and probably shorten the plug, piston, and valve lifespan. It is completely detrimental. No good will come of it.
  9. Rocketmanh5

    Rocketmanh5 Rockstar 100 Posts

    If you must do this follow Pikey's way. There's not a very good way to do so. As stated above also some high flow cats would work better in your application so there are no issues with O2 sensors. If you remove cats they will just put a straight pipe in its place with the threaded fitting for the O2 sensor into the pipe so they will remain in somewhat of a stock location. 9 times out of 10 though the CEL still comes on. The computer has a hard time adjusting to these parameters (I believe I used that correctly in that statement). Also double check your state's laws concerning catalytic converters. Even though with farm tags in our state if the vehicle is on the road even if it has a state inspection by a inspector you may know that let you slip by, the law will eventually hear and pull you over. In our area most get pulled over with duals since they all like 8 inch tips. In my opinion it sounds horrible to make one "loud", and I'm not some "old timer"(sorry if any offence to members not meant to be just a reference) I am 21. If you want a good loud deep sounding exhaust check into headers with good flowing cats and then do true duals and have a good flowing muffler and come out the rear or dump them around the spare tire. It has that loud that you are wanting along with a great tone and some gains. I'm afraid if you cut off your cats and left it be without telling the computer it's fine then you might experience drastic mpg loss along with sluggish bottom to mid end rpms.

    This is just my take on it not bashing you in any way. Just making sure you know what you may be getting into and what my take on the situation is. I hope it helped in some way. If you have anymore questions feel free to keep asking we're here to help each other!
  10. summitwhite11

    summitwhite11 Active Member 2 Years 500 Posts

    youngins, they have to make a lot of racket, and when they are fifty, guest will be asking, why do you have your TV turned up so loud, are you hard of hearing? To each there own.

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