Gutting Catalytic converters

[mike3026]

Okay then. Got it. So do you have to do anything to the o2 sensor.

[Starch]

I finally got around to getting the 2.2k Ohm resistors. Now, I know to replace the o2 sensor in the uppipe, but there is the main o2 sensor in the main exhaust piping. There are 4 wires running from it. Does anyone know if that o2 sensor matters and if it does, which 2 wires require the resistor?

The resistor only works for the EGT in the up-pipe. The 02 sensors post turbo (there should be two btw) cannot be fixed in this manner. You have a couple of options though. 1. Most commonly reccommended. Get your self a Cobb Access port. Use it as engine management and use it to clear the check engine lights. 2 Get your self 4 18mm spark plug non foulers install them in the bungs where the o2 sensors go then reinstall the o2 sensor the sensors will be getting a smaller sample and not throw the check engine light. 3. There is another form of wire resister to use on the o2 sensor wires. I havent done much research on this so you can if you would like. Im typing this fast so I may edit later any questions ask.

[Black X Dahlia]

Oh okay there's a hidden cat the factory manual doesn't tell you about on that pipe from the header to the turbo.

if you have an 04+ STi or 06+ WRX then there are only 2 cats. The 2.5L engine got rid of the cat in the Up Pipe, leaving the Cat in the DP and your Cat converter