Changing the TRD catback exhaust to full 2.5”

[Deathreaper]

I installed the nameless front pipe / downpipe combo with cat & res today and it got me thinking of the piping diameter of my exhaust system. The Nameless piece is 2.5” and most of the TRD catback is 2.5” with the exception of the green section (approximately 10 inches) as seen in the crude diagram below. I know the TRD exhaust receives a lot of criticism for its price and lack of proven performance so I think what I have in mind will help. I was hoping to get a shop (Lachute Performance) to remove the green section and weld a 2.5” T304 stainless steel piece with a flange so the entire exhaust would have a diameter of 2.5”. All of the other sections of the exhaust are 2.5” which makes me wonder why TRD didn’t simply make that piece 2.5” to begin with (maybe it wouldn’t connect well with the stock downpipe?). The input to the resonator is also 2.5" which makes it even more puzzling.

Anyways, I like a lot of things about the TRD catback as it sounds great without being too loud, saves a bit of weight, some performance gains and most importantly it allows me to avoid exhaust tickets. I would like your feedback on this little project – good idea? bad idea? I don't anticipate this would cost much.


Thanks!

[BC-Boy]

I would keep the trd and just weld a piece of pipe,cancel the factory flex joint with springs and bolt it up with a gasket, put a 6in piece of flex pipe like the Perrin, have you got a tune for the additional air flow ? personally I find this ecu doesn't correct well instead it trys to fight it and restore factory values.