Catalytic Converter Question

dek12285 · December 31, 2007

Hi I am new to the forum and i have a question for anyone out there that has any experiance with this question. I have a 2005 Silverado with a 4.3L and I am getting ready to put a new exhaust system on. I was wondering though if i remove the converters will it set codes in my computer and turn on the check engine light. I know that technicly it is not legal to do this but i live in a state that does not have emissions testing and i have removed cats off all my previous trucks and cant help but do it since they sound so much better. Also if it will set the codes does anyone know of a cheap way to trick the computer to think everythings fine. Thanks for any input you can provide.

Draenor · December 31, 2007

Yes it will set off DTCs. You could but a set of O2 simulators, it will trick the ecu, but the truck still will not run right.

IMO, keep them on there not that restrictive. At least get a high flow cat.

dek12285 · December 31, 2007

thanks thats what i figured since it had 4 o2 sensors. but ya thats probably what ill have to do is put hi flow cats on. i didnt really want to put simulators in since those cost as much as hi flow cats do. thanks

dek12285 · December 31, 2007

does anyone know of something cheaper than one of those expensive simulators

dlstewart01 · December 31, 2007

Even though you don't have emissions testing in your area, it is against Federal law to remove them.

Don

Zembonez · December 31, 2007

With the converters gone, it isn't going to run right. They are an integral part of the fuel management system. Why on earth would you remove them? You will gain nothing in the process. The "old school" removal of the converters went out about 15 years ago!

dek12285 · December 31, 2007

With the converters gone, it isn't going to run right. They are an integral part of the fuel management system. Why on earth would you remove them? You will gain nothing in the process. The "old school" removal of the converters went out about 15 years ago!

I would have to disagree with you on that one. i do know that the after cat sensors only monitor on weither the converters are doing there jobs or not. the before cat sensors are what monitor and adjust the fuel trim in the computer. converters are only for emissions to limit how much hydrocarbons are exiting the exhaust. now yes eliminating the cats only does increase power by 1 percent but the reason is not power just sound. the converters restrict flow of exhuast gases and the more exhaust i push through the flowmaster the more aggressive tone i will get

Zembonez · December 31, 2007

With the converters gone, it isn't going to run right. They are an integral part of the fuel management system. Why on earth would you remove them? You will gain nothing in the process. The "old school" removal of the converters went out about 15 years ago!

I would have to disagree with you on that one. i do know that the after cat sensors only monitor on weither the converters are doing there jobs or not. the before cat sensors are what monitor and adjust the fuel trim in the computer. converters are only for emissions to limit how much hydrocarbons are exiting the exhaust. now yes eliminating the cats only does increase power by 1 percent but the reason is not power just sound. the converters restrict flow of exhuast gases and the more exhaust i push through the flowmaster the more aggressive tone i will get

Well, I'm not going to argue with you... since you already have all of the answers. Get out that hacksaw and get busy. The next sound I expect out of you is a roaring catless V6 screaming by...

minibike132 · December 31, 2007

roaring catless v6

dek12285 · December 31, 2007

lol . no i didnt want to argue i just want 2 know if anyone knows of another way to trick the o2 sensors rather than spending 40-80 bucks for o2 sims. if im gonna spend that much ill just buy high flow cats to put on there.

redvett · December 31, 2007

All late model cat's are high flow including the OEM.

Zembonez · December 31, 2007

lol . no i didnt want to argue i just want 2 know if anyone knows of another way to trick the o2 sensors rather than spending 40-80 bucks for o2 sims. if im gonna spend that much ill just buy high flow cats to put on there.

The cats are made into the Y-Pipe on your truck if I am not mistaken. If you really want to go this route, I think you should start with a set of headers and build a new system off of that. I still think you should use new cats but that is up to you. With the headers you can begin to actually step up the performance of the engine while you change the sound. A little on the expensive side but it would be done right.

dek12285 · December 31, 2007

lol . no i didnt want to argue i just want 2 know if anyone knows of another way to trick the o2 sensors rather than spending 40-80 bucks for o2 sims. if im gonna spend that much ill just buy high flow cats to put on there.

The cats are made into the Y-Pipe on your truck if I am not mistaken. If you really want to go this route, I think you should start with a set of headers and build a new system off of that. I still think you should use new cats but that is up to you. With the headers you can begin to actually step up the performance of the engine while you change the sound. A little on the expensive side but it would be done right.

ya i agree and i wish i could just redo the entire exhaust system but the cheepest headers i can for my truck is 500 bucks and thats way to expensive for me right now. do you now of a cheeper brand that i dont know of. the only brand i can even find headers from is JBA. nobody makes hardly anything for the 4.3

Zembonez · December 31, 2007

lol . no i didnt want to argue i just want 2 know if anyone knows of another way to trick the o2 sensors rather than spending 40-80 bucks for o2 sims. if im gonna spend that much ill just buy high flow cats to put on there.

The cats are made into the Y-Pipe on your truck if I am not mistaken. If you really want to go this route, I think you should start with a set of headers and build a new system off of that. I still think you should use new cats but that is up to you. With the headers you can begin to actually step up the performance of the engine while you change the sound. A little on the expensive side but it would be done right.

ya i agree and i wish i could just redo the entire exhaust system but the cheepest headers i can for my truck is 500 bucks and thats way to expensive for me right now. do you now of a cheeper brand that i dont know of. the only brand i can even find headers from is JBA. nobody makes hardly anything for the 4.3

WOW... 500 bucks isn't cheap for sure. Small block stuff is half that or even less. 4.3 stuff is a little rare and I guess that makes it expensive. What about just coming off of the original manifolds with your new system? Looks like that might be the best way to go for the money.

dek12285 · December 31, 2007

lol . no i didnt want to argue i just want 2 know if anyone knows of another way to trick the o2 sensors rather than spending 40-80 bucks for o2 sims. if im gonna spend that much ill just buy high flow cats to put on there.

The cats are made into the Y-Pipe on your truck if I am not mistaken. If you really want to go this route, I think you should start with a set of headers and build a new system off of that. I still think you should use new cats but that is up to you. With the headers you can begin to actually step up the performance of the engine while you change the sound. A little on the expensive side but it would be done right.

ya i agree and i wish i could just redo the entire exhaust system but the cheepest headers i can for my truck is 500 bucks and thats way to expensive for me right now. do you now of a cheeper brand that i dont know of. the only brand i can even find headers from is JBA. nobody makes hardly anything for the 4.3

WOW... 500 bucks isn't cheap for sure. Small block stuff is half that or even less. 4.3 stuff is a little rare and I guess that makes it expensive. What about just coming off of the original manifolds with your new system? Looks like that might be the best way to go for the money.

ya thats pretty much what im gonna do. im just gonna use the stock y pipe and just cut out the cats and put a peice of pipe in its place. thought bout true duels but ive already got the money invested in the after cat part of the exhaust and that wasnt cheap. ya i dont see how anyone would pay 500 bucks for just headers and to top it off they arnt even full length. just shorty headers. hey if anyone out there knows of a brand that makes full length headers for my truck let me know. id love to get some just dont want to pay that much