Benefits of Removing Cat and Running Straight Pipe? - Toyota Yaris Forums

Bdaslug · 09-20-2007, 01:10 AM

I gutted my cat. and also I made my piping larger than stock. now I have a 2.5 in exhaust all the way. without the cat it's get a little bit louder. Depending if you have a straight through muffler like a N1 style. But it doesnt sound like a honda. Also your gas mileage will go down alot, Because the check engine light stays on without the cat. I actually tried both O2 simulators (mechanical and electrical) and the check engine light still comes on after a few miles. But you can feel the difference from the stock 1-3/4 inch to 2-1/2inch piping only at higher speeds. I am going to install a high flow cat to get rid of the check engine light and it should help my gas mileage a bit.

09-20-2007, 01:10 AM	#10
Bdaslug Drives: 07 Yaris 04 TSX Join Date: Aug 2007 Location: Laguna Hills Posts: 35	I gutted my cat. and also I made my piping larger than stock. now I have a 2.5 in exhaust all the way. without the cat it's get a little bit louder. Depending if you have a straight through muffler like a N1 style. But it doesnt sound like a honda. Also your gas mileage will go down alot, Because the check engine light stays on without the cat. I actually tried both O2 simulators (mechanical and electrical) and the check engine light still comes on after a few miles. But you can feel the difference from the stock 1-3/4 inch to 2-1/2inch piping only at higher speeds. I am going to install a high flow cat to get rid of the check engine light and it should help my gas mileage a bit.