Ok so my car is throwing P0171, unmetered air, running lean and what not.

From searching, Ive seen that some people think its the solenoid, others think its the bypass valve...

My question is how do I test them to see if they're bad.

My cars symptoms are the car runs sluggish, horrible gas mileage, and I already checked around for leaks. Both o2 sensors are new and the MAF is working fine.

Thanks in advance for the help

 

Engine power reduced???

 

nope.. just runs pretty sluggish.. oh and i forgot to mention that when i step on it, the engine seems to take a while to slow down.. the rpms go down slower than normal in neutral

 

Clean your TB and tighten down all your intake hose clamps?

 

is the car stock

 

Car is stock and i cleaned the carbon buildup in the throttle body about 5k miles ago... also the intake pipes are tight..

 

Bump

 

More searching still Nada... Anybody?

 

When I was getting 0171, I had to take a can of carb cleaner and spray around the engine bay and listen for a change in RPM. Turns out the compressing of the phenolic spacer I put in caused unmetered air to enter at where the IM met the engine block. Spray around the vacuum hoses and near the gaskets.