i just purchase a 02 wrx. all stock. only one problem. i am only holding like 4-5 pounds of boost. i tried my friends aftermarket boost controller on it.it holds 10 psi. but when i put it back to stock controller its back to 4 psi. what can i do to get back to stock w/o having to buy a boost controller.

 

what rmp what gear?

did you try reseting the ecu?

 

What is the peak boost that you see at 4000 rpm in 4 th gear? If that's too fast mph wise, what is the peak boost that you see at 4000 rpm in 3rd gear? You shouldn't see less than about 11 psi for completely stock.