I have a 2000 VW Beetle, automatic with 113,000 miles. The check engine light is on and the trouble codes read P0730 and P0740. When the check engine light is on, the car will go into reverse, but while driving it will not shift out of 1st gear. The check engine light will go off randomly, and when it is off the car will shift perfectly with no problems. A mechanic turned off the check engine light for me, the problems disappeared, but the light came back on a few days later. Is this a mechanical or computer problem? It only shifts poorly when the light is on?