Mark_B

Seen a few posts regarding flat spots on MY01 PPP, I did have the same problem around 4500 rpm, tried BP's new fuel which was better than optimax then tried this from www.scoobymods.com,(wrx/mods) (Link below) Replace the restrictive hose coupling that is in-line between the wastegate 'T' and the factory boost solenoid with a much less RESTRICTIVE coupling, made change and switched back to optimax, all problem sorted and it runs much better and pulls stronger all the way, good cheap mod and it works. hope it works for others.
http://www.scoobymods.com/forums/showthread.php?s=86361fe430da25edbb73fed6696787eb& threadid=1564

scooby L

Mark,

Where did you get the coupling from mate?

Mark_B

just get a 5mm dia pipe joiner from most car stores,(not halfords they didn't have any) same type of thing you use to connect air horn pipes together etc.
hope that helps

Spooks

Would this work for non PPP'd cars? Wouldnt say mine had a definate flat spot but certainly seems to die off a bit before coming on song.Dont wanna do this and cause any probs with it, anyone else confirm this?
Spooks

EMS

The "piggyback" PPP for MY01/02 only raises boost and keep standard ignition and fueling. The "flat spot" is caused by the fueling which is WAY TOO rich! Remove the PPP and get it remapped properly. (I did about 20 of these.....)

Mark.

Mark_B

with regards to non PPP give it a go, it only cost about a quid and you may notice a benefit, if not put it back to standard, try anything once you never know.
check the link I posted explains more.
As for remapping (expensive), I bought this car with PPP already fitted to save cash, and it aint that much of a problem to start throwing lots of money at it, unless anyone knows any better!
but when cars are less than 3years old its all about Warranty, which is why PPP is so popular.