Hi everyone..first time posting, problem w/ jetta

[Matt1100]

Im currently troubleshooting a problem on a 01' jetta vr6. Whenever its started up cold, mornings mostly, the car hestitates and stumbles as you give it gas. along with it is a bad rumble sound that comes from the exhaust that stops after 5 minutes. After about 10 mins of driving, its fine. one time it kept doing it for a good 20 minutes. Also, wheverever it feels like it, the car wont shift into 3rd gear, it wont even rev as well, no matter how much gas i give, nothing happens, jsut stays in second gear at about 25/30 mph and it wont move above that- this happens rarely though, whether the car is cold or not. did all typical checks- fluid, etc.. connected the to obc and cleared the check lite that pops up once in a while, made no differnce. the check light is always on though when the car is cold. ..any ideas? any info is appreciated. Thanks, Matt

[boschmann]

What code is coming up?

[veedubmechanic]

have you replaced your fuel filter recently? how about the coil pack?

[Matt1100]

Fuel filter was replaced a few months ago.
Can the coil pack cause the problem based on the symptoms?
the code is for the mass air flow sensor, but theres nothing wrong with it.