ok i had a project focus a while ago but dicided to buy a dependable fast daily driver car. so i got myself a 2004 srt-4 and love the thing to death exsept! my boost doesnt peak nor hold. ill barely peak 10 and hold 9. ive already check all my piping make sure there are no leaks but everything seems fine. although my wastegate rattles while reving... could the wastegate be causing this?

 

vacumn lines and boost leak test the bitch, also check to see if the arm on the wastegate is bent. How many kms do you have? Quick fix would to be get a new wastegate(Aftermarket of course) and set it for 15 hold 13 so your back at stock settings.

Jordan