That will fix the boost leak, but you gotta be careful because you might be disabling another device in the process. If that hose is there to feed clean air into the Evap solenoid then cool. If the hose is there is vent into the intake, then a checkvalve would effectively disable this. One of us will figure this out. At least we have the ability to control the boost leak in this particular area of the system for now.
Enter "the box". The box modifies the signal to the ECU as to what boost you're running. So if you're running 20 psi of boost, the box only tells the ECU that you're running for example 10 psi of boost. The ECU notices that it's not the minimum required boost and throws the underboost code. That's my theory.
Try turning the adjustment on the box down to less aggressive and see if the code goes away. This should increase the broadcast boost pressure the ECU sees and *may* remedy the issue with this code.
And, yes, the leak might make a difference too...
Bumping this thread to see where we ended up. Anyone been running a check valve on that hose that goes back into the intake? I've noticed it's a terribly weak connection fitting overall, is that the actual reason for the leak, or is it just the fact that it's being routed to the intake in the first place? Where did we end up? That dyno on page one actually looks worthy of pursuing this to it's final end.
RAW Big Turbo, tuned to 250+whp on p93
LSD, FX400, Okadas, 550cc, ported t-mani
NightOwl Racing BC Racing with SWIFT Spring Suspension set up
ATM FMIC, ATM Fenderwell Intake
VanHook CF Rear Diff, doorhandles, hood vents and duct covers
Advan RSII 17x7.5, rally stud conversion
can you post pics of this and list the part (check valve) that you used on this?? thanks
I have a pic but not a part number. It is just a typical 3/8" (I think) check valve with the arrow on the valve pointing towards the chargepipe.