are the 04 and 05 uppipes exactly the same on the sti?

 

The up pipes for a WRX have a cat. The up pipes on the STI don't.

 

thanks, but is the uppipe any different from the 04 and 05 sti? i'm looking to put a 04 sti up into my 05 wrx...this should fit minus the egt sensor? this is not an o2 sensor right?

 

the upipe for the 04-05 are the same.
It should fit without a problem.

It's an o2 sensor(i think). You need to do the CEL fix or you'll get a CEL.

 

The O2 sensor is in the "header". The EGT sensor on the WRX is in the uppipe. You'll need the EGT cel fix which is $.99 worth of resistor from Radio Shack.

 

The resistor you need is 2.2Kohm and 1/2watt. You can remove the EGT probe altogether and disconnect it at the harness. Then plug the resistor into the remaining harness half and tape it up.

 

Thanks , are there any negative effects (other than to check the uppipe cat) of removing the EGT sensor? does the ECU use this for timing/fueling anything like that?

 

Nope. The ECU uses it to make sure the uppipe cat is working correctly. As long as you use the resistor mod, you won't get any CEL's.

Your car is actually much safer without the EGT probe in there. If that thing ever fails, it's going right into the turbo blades.