Toyota Nation Forum banner
1 - 16 of 16 Posts

·
Registered
Joined
·
47 Posts
Discussion Starter · #1 ·
Has anyone cut out there catalitic coverter from there exhaust, it seems pointless to put the dual exhaust when the flow is still being restricted by the coverter.
I put the dual exhaust on my truck, the air raid filter and it does sound better but I really dont think it gives any horsepower gains, and to spend 1300 on the duals, 400 for the filter for some sound and no performance is a bad deal,
So I want to cut the converter right out, will it affect my truck at all or will do you think it will finally open up things and let it run free
 

·
Registered
Joined
·
676 Posts
Has anyone cut out there catalitic coverter from there exhaust, it seems pointless to put the dual exhaust when the flow is still being restricted by the coverter.
I put the dual exhaust on my truck, the air raid filter and it does sound better but I really dont think it gives any horsepower gains, and to spend 1300 on the duals, 400 for the filter for some sound and no performance is a bad deal,
So I want to cut the converter right out, will it affect my truck at all or will do you think it will finally open up things and let it run free
Well, you're not the first one to think of doing this. I've seen many arguments over whether or not it's good for the truck, good for the environment, and if you'll get improvements in gas mileage. One thing that holds true through everything I've read is that you'll get error codes by removing the O2 sensors, so it's not as simple as just removing the converters.
 

·
Precision driver
Joined
·
2,105 Posts
Lets keep it clean, guys.

If you do decide to get rid of those cats, you'll just need to find out a way to make it so the codes and CEL don't come on. I've heard of guys that are finding the resistance measurement put off by the O2 sensors and soldering a resistor in their place. Just make sure to do the research by searching for the right one (Google, and dare I say, TS), or grab a voltmeter and use it to measure it:thumbup:
 

·
Registered
07Tundra Reg Cab SR5
Joined
·
53 Posts
don't know what was said above since it looks like some posts were deleted but i had a 05 silverado VMAX 6.0l that i removed the cats from and went dual 3" pipes all the way back. sounded incredible and really boosted performance!! only think i didn't like was that that it lit up the check engine light.

luckily here in az we don't need to pass emisions until the car is over 5 yrs old and only if you live in a bigger city ie: tucson, phx maybe flagstaff so it didn't matter to much that it had engine light on. but boy did it move.

i'm sure the 5.7 in the tundra would feel liberated and free. i've thought abot doing it to mine. not sure yet though. if you do it let me know how you like it!!
 

·
Registered
Joined
·
387 Posts
Aww. Why did you delete it? I missed it. Sounds like I missed a good chuckle. There should be a collection of deleted posts for people to see, am I the only one that sees people being assholes hilarious? I can't be, "house" is still on the air.
 

·
Registered
Joined
·
3,492 Posts
Aww. Why did you delete it? I missed it. Sounds like I missed a good chuckle. There should be a collection of deleted posts for people to see, am I the only one that sees people being assholes hilarious? I can't be, "house" is still on the air.
I missed it too (which is a problem if I'm not glued to my computer 24/7 to witness this kind of things), I was away for the weekend.

I love the show "House", since you won't get that kind of politically correct person in real life (or not at all times anyway), you might as well enjoy it from a TV drama :lol:;)
 

·
Registered
Joined
·
387 Posts
I missed it too (which is a problem if I'm not glued to my computer 24/7 to witness this kind of things), I was away for the weekend.

I love the show "House", since you won't get that kind of politically correct person in real life (or not at all times anyway), you might as well enjoy it from a TV drama :lol:;)
I sometimes try to be like him at work, but instead of the hilarity that comes across on the tv when he does it, people just think I'm a dick. Life's just not fair.
 

·
The womaneater!!!!!!!!!!!
camry gen4th
Joined
·
432 Posts
if you take out your converter it should should be fine. the o2 will just read in closed loop mode. I don't run a cat. and you'll probably free some hp but your exhaust will kill you if you like that... I know I do.
 

·
Registered
Joined
·
3,492 Posts
I sometimes try to be like him at work, but instead of the hilarity that comes across on the tv when he does it, people just think I'm a dick. Life's just not fair.
:lol: I know, people just can't except the hard truth without the need to sue the offender :lol:;)
 

·
Registered
Joined
·
43 Posts
Way back in the 80's while residing in California, I bought a new Ford 1/2 ton step side truck with a 302 V-8. A friend of mine knew of a shade tree mechanic that would strip off all the smog equipment and gut the CAt. Converter, make it run sweet. When the job was done I didn't feel any more power and my gas mileage dropped by 3 mpg. A few years later they mandated Somg Testing and I had to get rid of the truck.

You better think long and hard before you make major changes to the trucks emissions. It could come back to haunt you in a number of areas. How about warrantee issues? I vowed after that episode to never tamper with my truck's design.
 

·
Registered
Joined
·
676 Posts
Way back in the 80's while residing in California, I bought a new Ford 1/2 ton step side truck with a 302 V-8. A friend of mine knew of a shade tree mechanic that would strip off all the smog equipment and gut the CAt. Converter, make it run sweet. When the job was done I didn't feel any more power and my gas mileage dropped by 3 mpg. A few years later they mandated Somg Testing and I had to get rid of the truck.

You better think long and hard before you make major changes to the trucks emissions. It could come back to haunt you in a number of areas. How about warrantee issues? I vowed after that episode to never tamper with my truck's design.

To be able to refuse warranty work on the basis of non-oem parts, the dealer must be able to prove that whatever modification you did to your vehicle directly caused the malfunction.
 

·
Registered
Joined
·
43 Posts
My guess is that gutting a CC is a major change to the system, something that would prevent computer diagnostics, a legit reason to refust to work on the unit under warrantee. But that's just my opinion, Have at it. You paid for it and can do with it as you please. I learned my lesson the hard way.
 

·
Drive it like you stoleit
06 x-runnr
Joined
·
111 Posts
The taco guys have been talking about this topic for awhile now and i've yet to hear any real mechanical backup of some arguments. My buddy(master technician) told me that removing cat's are easily done, yes they cause backpressure which unless your running a race car you vehicle needs. Look at some dyno charts on guys running full headers and exhaust and yes they make an extra 10-17 hp at 4700 rpm they also lose 10-17 hp from idle to 4000rpm. So in otherwords your losing power down low where you do most of your driving and gain it up top. Running no cats is horrible to the enviroment, and im no tree hugger but it's the quivalent of driving 3-4 diesel trucks for you guys with a tundra and straight pipes. The other thing is usually the small cats(on your manifold) have the 02 sensor built in and send info from unburnt fuel and temp to help your truck run smooth. So you remove these sensors and it will set off your check engine light, which you can buy an 02 simulator for and it just loops the electronics and tricks your computer or buy a scanning tool and reset it twice a day when the light comes on.
I've yet to purchase headers and exhaust but a highflow cat is actually half as restrictive as your muffler so simply removing your cat isn't gonna fetch you any power. The larger diameter pipes will sound nice and make more power up top but you lose it down low so it's kind of a win(sound) win (high end hp) lose(money) lose(headaches of getting a system that sounds right and makes good power) situation.
 

·
Registered
Joined
·
127 Posts
I've seen many arguments over whether or not it's good for the truck, good for the environment, and if you'll get improvements in gas mileage. One thing that holds true through everything I've read is that you'll get error codes by removing the O2 sensors, so it's not as simple as just removing the converters.
Fact: horrible for the environment. Manufacturers have put a ton of effort into making vehicles cleaner and more efficient due to regulations and consumer demand (gas prices). I did a test with a 4-converter 5.0L mustang on a sniffer with and without cats, hydrocarbons were increased by a factor of 10. Even if you can live with the smell at a stop light, remember that you'll polluting as much as 10 trucks.

Power improvement: Maybe, but usually not worth mentioning. The 5.0L motor showed a 1-1.5% improvement in power, which could have just been differences in dyno conditions. I admit that *some* vehicles with restrictive converters might benefit more than others. Most of the time the true restriction is in the design of the headers... So look there first.

Gas mileage: maybe, if you had more power across the board. Basically the question here is: does removing the converters increase engine efficiency? Probably not in any way you can measure it...

Negatives: other than the environmental issues, you'll set a code. This truck will eventually get 02 sims, so you can work around that. However, more and more states are going to sniffer tests and even if you're not impacted directly by that test (which can't be passed without cats) - your resale will be impacted.


Don't do it, there are better ways to get more power out of a great truck without seriously impacting pollution, decreasing your resale, and no real seat of the pants improvement in power.
 
1 - 16 of 16 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top