Hi I've had my 04 wrx for a year now.
It's all standard, but it seams to struggle on power up to boost. Sometimes its very Resposive but most the time its not. I've just started noticing a backfire between gear changes sounds good. just abit worried about it. Am I being abit ott or do I have a problem? Thanks

 

are you sure its not the hot weather lately, turbo charged cars dont usually like it.
backfire sounds like a symptom of an aftermarket vta dumpvalve.

 

Thanks for the reply but No mate it's not the hot weather had the power loss though the winter as well. and I'm still running the original dump valve.

 

check for boost leaks but they do pop a bit when its warm outside.

 

As tubby says check for boost leaks in the pipe work. My old VTA dump valve used to create pops between changes until I swapped it out. Might be worth plugging a fault code reader in also to see if you have any codes stored?

 

Cheers lads for the help will check for a fault. Just seams flat up to boost.

 

That'll be a wrx for ya