Does the STi up pipe have a sensor hole in it like the WRX does? I know it dosnt have a cat, but I am looking for an aftermarket up pipe and need to know if the aftermarket pipe needs a hole or not.

Thanks,
Nick

The STI doses not have any type of cat in it or a EGT port, the EGT is not used
On the STI and there is no port for a EGT sensor.

The Helix Up pipe is ¼ larger in diameter than a stock STI Up pipe.
The helix will give you 10HP gain works great!!

You can use the STi uppipe, just get a 2.2k ohm resistor to stop the CEL.

Now the STI HAS NO EGT So you do not need a resistor!!

This thread is asking if an STi uppipe can be used on a WRX. Since the WRX ecu is expecting an EGT signal from the uppipe and the STi has no provisions for one, you would need the resistor in your WRX wiring harness where the EGT sensor was plugged in if you wish to avoid the CEL.

is it worth upgrading the sti upipe to a helx upipe or should i spend money on something else

If you have an STi, you have little to gain by changing the uppipe. The turboback makes more power, and better bang-for-the-buck.

No, it wasnt aimed for a non STi. I have and 03 WRX and am lookin to buy an STi. Proably gonna get a Gruppe-S header with a helix up pipe (STi). My origional idea was to take the Gruppe-S up pipe off of my 03 and put it on the STi and stick the stock STi one on the 03 before I sold it. But since that wont work. Does anyone made an up pipe without a hole in it? Aftermarket proably weighs less and is better flow than stock.

Nick

Sorry, first post seemed as if you wanted an STi uppipe for an EJ20.

As for weight, I doubt a quality uppipe is significantly lighter than the OE piece. As for flow, you *might* be able to improve that, but I dunno if you would get your money's worth out of it, or enough power to justify the trouble of changing it. Even by removing the cat in the WRX uppipe, the gains are only about 10 hp. With no cat to remove, I doubt there would be a significant difference. I would not replace the uppipe unless I was also going to a larger turbo and was concerned about spool up.

Gruppe-S header is $399 with a helix up pipe for $499 shipped. Not a bad deal. If I didnt like it could most likely sell it for what I paid.

Nick

I have the Gruppe S type II header and I like it. I left the oem uppie in place. It was not worth the hassle and cost for minimal gains{unless you are swapping out the turbo}.

Thanks. Did you notice any power increase?

Nick