Nasty4d

1996 gsr has 2 o2's on the cat 1 before the cat and a downstream after the cat... will gutting the cat affect the downstream o2? will it throw any cel's? with out having a chipped ecu is there any way to get rid of it?

Fabrik8

It will often throw a CEL, yes. There are ways to get around that, but they're all pretty ghetto and usually involve spacing the sensor out of the exhaust stream or making a dummy sensor using resistors to fool the ECU.

I'm going to say what I usually say (which isn't very popular but I don't care) and tell you to get a high flow cat if you think your stock cat is too restrictive for the power you're trying to make. Have an environmental conscience, and think on a larger scale than just doing something the cheapest way possible. There are cats out there that can handle many times more power than you will ever hope to make with a 4 cylinder Honda, so there isn't any excuse except for spending money.

Nasty4d

thanks for the info... it isnt for me its a friends car, i wasnt sure if a highflow cat would solve the issue either seeing that most are a straight thru design. my buddy is trying to put together a cheap dailey driver and was just trying to make the stock exhaust a little more free flowing for better mpg's... thanks for takeing the time out to help give me some advice