Not sure where exactly to put this since it could be transmission related, electrical, etc.. But i'll repost it to here and hopefully someone can help.

Hey everyone, hope you can help me out here. Just bought an 05 audi a4 a week ago and 2 days after i bought it, it started shuddering and stalling going jnto drive and reverse (tiptronic trans btw). The next day i unhooked the battery for 10-15 min and hooked it back up. Traction control light came on and it went into reverse perfectly once and then back to shiddering and stalling out. Once car is in gear and driving, it runs beautifully. Shifts well, drives smooth. I next went and bought a vcds vag com to help aide me to find the problem. It came up with simple malfunction codes for a oil level sensor and some door, window, etc malfunctions. Those all cleared and havent come back. The only code that wont clear is a steering angle sensor code. Are there any specific test i can run with the car on to put it in gear and see whats making it shudder? I wanted to check the tcm under the passenger seats floormat/carpet, but i cant get the carpet to pull up w/o thinking it will rip something. Its raining terribly so tomorrow i hope to be under the car, bur for now any ideas or was to help?