Accelaration problem while driving my 2002 audi a4 and pressing the gas, the stops accelarating and the engine revs up as if it has been put into neutral. i pull to the side of the road, turn car off and then on again to be able to drive again. this happens daily. any suggestions?

Your brakes appear to be dragging i.e. brake pads still contacting the rotor. It could be air in your hydraulic braking system. Have the braking system flushed and bled.

Airflow mass meter needs to be checked

What oil got changed? Engine oil? Trans. fluid? How long have you had the car since the output shaft seal was changed? What codes do you have coming from the TCM?
Improper fluid levels or incorrect fluid type will cause severe problems with these units.

Do it yourselfers can go on ebay and buy scan tool interface and program to diagnose vw,audi.Ihave it my self and its paid for itself many times over. Your only oter option is to go to daeler for scan and repair.Its possible to damage car by driving in this condition.

most likely a air bubble in your system. get it up to temp open up your reservoir use something that will fit in the opening and put coolant into it rev engine up a bit until you see bubbles coming up. when you did the engine did you replace cooling system parts like t-stat or water pump? purging the system of air will take a little while good luck hope that helps

timing belt

replace the idle air control valve.(on the bottom of the throttle body) may be easier to remove the throttle body and turn in upside down to remove the idle air control valve and hoses. be sure not to pinch the gasket. after u do that be sure to replace any coolant that may have came out. then, start the car, rev the car to 3000 rpms till the radiator fan comes on , then let the vehicle idle for 20 - 30 mins . the computer should relearn the idle. local honda dealer should have the valve in stock,

The ignition switch is faulty. CRC may fix the problem.

CHECK YOUR BRAKE PADS FOR WEAR,( BRAKE PADS HAVE WEAR SENSORS) AS FOR THE NOISE, IF ITS COMING FROM THE WHEELS, SOUNDS LIKE A WORN OR DISTORTED BRAKE DISC...HOPE I WAS OF SOME HELP..

there is no Transmission oil check on Audi's, What I mean is that you have to bring it to a shop for them to check it. Totally retarded but I have the same issue I cannot check mine and I have a 2000 Audi A4 2.8L