new mass air flow sensor and I'm still having the same problems

[1 Unique Tsi]

I have a 95 tsi front wheel drive all stock for now. Well, here is the problem,... I purchased a new mass air flow sensor and I'm still having the same problems. When the old sensor was plugged the car bogged down, sputtered and popped, and the power was very poor. After a while, I discovered that without the mass air flow sensor plugged in, the car runs great! It still bogs down after about 5,000 rpm at full throttle. If I gradually give it gas and stay at a steady throttle position, it picks up moderately. I also noticed raising the rpms at about 3-4,000 steadily in parked and in neutral the bov seeps air, but still blows off nicely. I know it's going to have to be replaced. But back to the sensor, could it be the pcm? It has to be a sensor problem. I'm going to run a boost leak test as well to see if I have any leaks and see if the performance gets better. I replaced almost all the vacuum hoses with silicon hoses. I need help you guys, I'm ready to ride!!

 

[tenn-gsx]

If the bov leaks enough for you to notice with the engine running and no load then that is most likely your problem. Fix that and im pretty sure your problem will drastically reduce if not go away completely.

 

[1 Unique Tsi]

The bov doesn't leak at idle though. Just only when the rpms are raised and steady.

 

[tenn-gsx]

Im sure it does. Just not enough to see or hear with the engine running. Do a boost leak test and fix all leaks.

 

[1 Unique Tsi]

Ok, sure thing man! You think it could be a bad sensor as well, besides the mass air flow?

 

[tenn-gsx]

Anything is possible but keep it simple. After you fix the leaks if it still runs like crap go to advance or autozone and see what codes they can pull.

 

[97 gst turbooo]

i had this same problem. after changing the MAF sensor and replacing my greddy type s with the hks ssqv problems disappeared. try to adjust your bov tighter so it doesn't leak as much and check for boost leaks, mainly at the TB. how old are your spark plugs?

 

[steadman1988]

if your bov is leaking that badly then at idol and off boost it won't be leaking out, it will be leaking in. either way it will mess up your fuel mixture drastically and without your mass plugged in your car is faking it on the fuel mixture and it's probably better off faking it with a bad leak. So with the mass plugged in off boost your running lean due to the extra unmeasured air coming in and on boost it's running rich do the the measured air escaping.

 

[alfred480]

Try switching to a diverter valve by attaching a hose to where the BOV would usually dump the air to the atmosphere and if your intake is still stock there should be a pipe sticking out after the mass airflow sensor, attach the hose there and you got yourself a diverter valve. That is how it should have come stock anyways with a diverter