Engine check light on and when you run the vehicle, not enough power is driven from this car..

SOURCE: 2003 Audi A4 1.8T Check Engine light on

The CEL means there is a Diagnostic Fault Code stored in the Engine Control Unit. There are 1000's of DTC's, so you will need to have it read by a Code Reader. Auto Parts stores like Auto Zone, Pep Boys, perhaps even Advanced Auto often will read the code for you; but by law they cannot clear the codes. Many codes do not cause drivability problems, severe ones will trigger the ECU to run in a Limp Mode, which would require repair work before any trip longer than a few miles. Hope this is helpful.

SOURCE: The check engine light came on ou car last night.

could be but have car scanned some auto stores such as auto zone / advanced auto do it for free the code will give u a start point---may be a mileage service request or may have a problem they car also reset the code for u

SOURCE: Shaking engine, weak power, blinking check engine light

You have a bad coil pack, they usually crack from age and heat. It's best to replace them all. Check for a VW recall on this item.

SOURCE: Hard Acceleration causes power loss. Vehicle

Download this link and find your Service manual for your vehicle. It will serve you well and to keep for future reference

http://ezinearticles.com/?Find-the-Free-Auto-Repair-Manual-You-Need-Online&id=92717

SOURCE: Getting Error codes P0732, P0734, P1529

Sounds like a dirty of faulty speed sensor. They can be removed and cleaned. Better off replacing. Do check the wires to the speed sensor. Trace wires from tranny to instrument cluster and make sure they are all in tact and clean.

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