I have a 2006 cobalt ss/sc I just bought it from a used car dealer. It only has 4 psi the entire time I get on it. Any process of elimination I could have ? I'm about to order a bypass valve. Any other Ideas? I have an injen intake also. 85,000 miles

 

does it throw a check light? if it does dis connect the battery and see if it still does it .... my car did that alot until i replaced the throttle sensor.

 

No, the first few days it threw the maf code but now it doesn't. I assumed it was from sitting. Now it doesn't have any codes

 

pull the bottom hose off the bypas valve and plug the hose...see wat hapends..

 

find the vac line coming from the intake manifold and follow it over to the boost bypass solenoid and unplug the vac line then plug and see if it starts shoving more then 4psi

 

Not trying to be an ass, just asking, did it have these issues when you bought it and if so why did you buy it?

 

^ this and yea check your bypass valve

 

I had same issue... was bypass valve.

 

I bought it in NYC so I couldn't notice the boost in first gear.
And I guess I'll order the bypass valve

 

So are you saying you couldnt get on it hard enough because you was in a big city.

 

Yupp

 

hmm..i like seeing all these post right around the same time that I am having a similar issue. is the bypass valve on the supercharger the black circular thing close to the throttle body?

 

yes it is but you need to diagnose wether it is the the bypass actuator or the solenoid if the solenoid goes bad it will always keep the bypass actuator in a no boost position if the bypass acuator is bad it will have the same symptoms so you need to diagnose which one it is before you spend your money

 

thanks for the advise...and if I do what you said earlier

..."find the vac line coming from the intake manifold and follow it over to the boost bypass solenoid and unplug the vac line then plug and see if it starts shoving more then 4psi"

and it does start pushing more boost would that tell me its the solenoid or the actuator?

 

if you unplug the vac line and plug and it shoves more then 4lbs that means its the solenoid

 

thanks...did this last night and after it was plugged it sure went past 4lbs. thanks for the help mrbelvedere

 

I put a new bypass valve in, 15 psi.. Thanks for your help everyone !