[dsawran]

I was talking to an custom exhaust builder and found out the TRD/Borla dual exhaust cat back has 2 cats built in after the muffler. He believes that is the reason there is so much drone at the 1800 rpm mark. He also said this cuts down on the sound significantly. THey are not sensored and really arent needed. I changed out my muffler with a magnaflow and they are removing the 2 cats on tuesday. I may be late in finding this out just thought I would share this with you. I will let you know if it makes a difference not having them.

 

[dogstate]

No cats after the muffler on my Borla set up.

I did not know the TRD exhaust had two cats. Doesn't surprise me being a Toyota part.

-rockstate

 

[dsawran]

No cats after the muffler on my Borla set up.

I did not know the TRD exhaust had two cats. Doesn't surprise me being a Toyota part.

-rockstate

The cats are built in the pipe after the muffler right where it turns to go over the axle.

 

[Mr. Creosote]

I bet those are resonators, not cats. It wouldn't make sense to have any cat that far back in the exhaust because they would not get hot enough to work.

 

[dsawran]

I bet those are resonators, not cats. It wouldn't make sense to have any cat that far back in the exhaust because they would not get hot enough to work.

I said the same thing...I will find out for sure tuesday. I'll get some pictures of whatever they are and will let you know if it makes the sound any different.

 

[Mr. Creosote]

Here is an emoticon to represent what you are doing to the resonators Tuesday.

 

[jeepnuts311]

I Wouldn't use that exhaust guy anymore.

-Tim

 

[dariusld]

I Wouldn't use that exhaust guy anymore.

-Tim

X2

 

[dsawran]

Thanks...to be honest it is probably more that I didnt understand what he was saying then him being wrong. But either way I am looking for more sound so removing them will only help, Actually it will be like the other guys Borla just straight pipe no restriction. I will let you know.

 

[greg hazlett]

Are there any 02 sensors anywhere around it? No..I know this as I took my stock system off and put on a Magnaflow and then a Borla and can say for a fact there are zero cats where that idiot said.

 

[dsawran]

Ok. Here is the deal. First I was way off base as to what I thought he was telling me...Sorry. There is indeed 4 cats on the tundra 5.7..There are 2 right after the header flange then the O2 sensor and then 6-8" past the sensor there are 2 more. They did remove mine and it has made a big difference for sound. I also (with no proof other than knowing my truck) can say it improved throttle response. Again I have nothing to prove that statement but I believe it to be fact. The sound is incredible better more of a rolling rumble you expect from a large V8.

 

[MacCTD]

Hope you saved them incase you ever need to pass a smog test.

 

[billyboy123]

the only vehicles that have cats after the muffler(s) are on pretty heavy duty diesels ( 1 ton and up) or vehicles with a gvw well over 10k lbs. its a resonator.

 

[dsawran]

the only vehicles that have cats after the muffler(s) are on pretty heavy duty diesels ( 1 ton and up) or vehicles with a gvw well over 10k lbs. its a resonator.

I wrote today that it they were in front of the muffler but after the intial cats and O2 sensor

 

[FLDak]

Hope you saved them incase you ever need to pass a smog test.

If he is from Jacksonville, FL no worries; FL has no state inspections.

 

[bilztrd]

Your Lucky....The CA smog police would be all over my ...