Hi, can anyone tell me the best way to replace the pre cat up pipe on a 03 wrx? do you remove the turbo and go at it from above or take of the headers and have a go from underneith. just asking so I can get all the gaskets etc that Ill need before I start the job.
also thinking about fitting a highflow downpipe would it make the job easier to do both at the same time?
Any advice would be most welcome.

 

do both at the sane time and then can just replace all the gaskets.

 

on a classic you can do it without taking the headers off however youd have to drop the subframe, and of course get underneath to do the up-pipe bolts...so as i had the full header system to replace the whole lot came off and i did it that way. cant imagine a newage car been MUCH different?

Yes would deffinatly advise doing both at the same time. Just go weigh up the job if you can undo a few nuts and bolts your away aslong as youve got the tools!

 

I did this a few weeks back and it was a t@wt of a job.
This is how i did mine

remove the downpipe as it needs to come off to get to a couple of the bolts on the uppipe
remove the part of the headers that connect to the up pipe
unplug the egt sensor
unbolt the uppipe from the turbo
unbolt the drivers side engine mount
jack the engine up then the uppipe will come out from the bottom
it is a bit of a fiddle but it will come out.

If your uppipe doesn't have a bung for the egt sensor then you will need a 2.2k ohm resistor to put in the plug so you don't get the cel light on.

Then get it remapped.

Dave

 

When I did mine, I removed the 02 sensor from the manifold so I could remove the heat shields as well, Was an awkward job but not as difficult as I thought it would be, there is a guide on one of the american subaru sites for installation of a perrin up pipe and I followed this, but also remeber if you are changing downpipe then the heat sields need trimming to clear a bellmouth as the original downpipe is a single pipe and it blocks the wastegate side of the turbo. I allowed a full day to change the 2 as I was only using axle stands, a pit or ramp would be easier. Also a lot of the bolts can be tight to remove,

 

Thanks for all the info. I found the perin guide and it will be a good help. I currently have a PPP ecu fitted does anyone know if I will need a remap after I have changed the up and down pipe?
Dan.