Are cats needed?

[ocelot]

hello im new to the forums and i just bought a 1997 two door tahoe and i have a question involving my truck running cats. Can you run cats without tripping any codes? Has any one on hear ran there truck with out cats, did you notice a difference in power, mileage, and was there a noticeable amount of noise produce in the cab?

thanks again guys this forum is pretty awesome

 

[SunlitComet]

You would trip codes and as a result screw up your performance. It also may be illegal where you live.

 

[destroyer1362]

You can run it without cats and you can tune the codes running without them cause out. And get it tuned to run without them. Sound will be a little different, cant describe it, it will definitely smell though. And if your state does the sniffer test ur sol come emission time. imo If you get rid of ur cats do it for a reason, like for installing LT headers or something.

 

[retorq]

You would trip codes and as a result screw up your performance. It also may be illegal where you live.

It's illegal everywhere.

With technology today there is no need to rip off your cats. You can make as much power with them as without.

 

[TahoeTX]

You don't want to remove your cats becuase they are required to pass inspection in most states. There isn't much performance gain from removing them anyway and it will make the car run different because it throws the computer off. Cats help burn off excess gas vapor that wasn't burned in the combustion process and it also collects other harmful fumes in the exhaust. It's basically an exhaust filter. Adding a cat back system with an aggressive sounding muffler will give you all the power and sound you want.

 

[Brandon X]

If you're state has emissions then you have to leave them on, if you doesn't, I say it them off. Yes you will throw a code, but it produces slightly more power and it sounds better IMO. Not to mention you can get $50+ for a cat.

 

[ocelot]

thanks for your input guys i have no admissions were i live, im just looking to run a new exhaust system(headers back) and wanted to see what is worth my time in money when doing it

 

[SunlitComet]

Go performance for the whole thing then. I am planning for Edelbrock shorties, Magnaflow dual cat assy. and flowmaster rear assy.. Will cost about $1300 total and is 50 state legal And the replece each o.e. part by direct bolt on. Can't wait to do it.

 

[nomad]

Running without cats

First, you can run without cats and not generate codes. I have helped friends do this (only to have them put them back on for inspection purposes) so I know it works.

That said there is little to gain removing them, first they are flow through and provide little if any back pressure. It's not like the 70's where Chevy used Platinum coated bebe's that were very restrictive. All your doing is subjecting yourself to problems. You would do better changing exhaust manifolds for free flowing headers and set of flow master mufflers.

Unless you live in a place where there is only leaded fuel do yourself a favor and forget removing them!

 

[Bad bow tie]

It's illegal everywhere.

Not in Michigan.

 

[Brandon X]

Yup.^ lol

 

[97yukon]

cut em off lol. i have longtubes and ran pipe from the collector back no cats. got the rear o2 deleted and no code. the emission test does not pick that up. ive gotten two stickers since i did it and no problems at all.

 

[bowtiefreak]

A visual inspection could be a problem even is the truck passes the sniffer test.

 

[ocelot]

lol i must say im pretty torn now on what to do with my exhaust system

 

[destroyer1362]

There's always ways around this sort of thing. Buddy of mine just got a $80 inspection, he has not cats. You just need to know the right people and the right places to go..

 

[Jim_Rockford]

Its a federal law ,states have no say, Only thing they can say is if you are going to get a visual or a sniffer test on the inspection but a federal law states you must have cat, As stated before they do not hurt power, Vortec truck cats are pretty much the highest flowing cats around. You gain no power by removing them, And one day when you get caught without em, Its gonna hurt the wallet.

 

[Bad bow tie]

Its a federal law ,states have no say, Only thing they can say is if you are going to get a visual or a sniffer test on the inspection but a federal law states you must have cat, As stated before they do not hurt power, Vortec truck cats are pretty much the highest flowing cats around. You gain no power by removing them, And one day when you get caught without em, Its gonna hurt the wallet.

It may be a federal law, but residents of Michigan do not have to have any sort of emissions/sniffer/visual inspection etc tests whatsoever. That said, if I wanted to cut them, I could and no one would know.

We are the automobile state and don't have to go through any of that emissions ********.

 

[Danny_Z56]

I would say to just get aftermarket highflow cats and a cat back exhaust system.

I once "gutted" the cats on a '98 Crown Vic i had,just for ***** and to see if i seen any performance increase.

Not only did i NOT see any improvement,but it seemed to lack bottom end punch/torque and the car felt like a dog and got shit gas milage....It seemed like i had to give more throttle to get the car to move like it did before i gutted the cats.

I ended up buying a set of used cats from a '99 CVPI and putting them on.Man what a difference....The car felt like it had balls again lol.

 

[bowtiefreak]

I love my high flow cats..Magnaflow.

Until I put them on I was blowing out a cat almost once a year

 

[SunlitComet]

edelbrock shorty headers, magnaflow cat assy., and flowmaster cat-back. $1300 total. All bolt on. 50 state legal. Done.