After cleaning throttle body on 2001 VW GTI 1.8 T car will not idle and check engine light epc light and traction contrl light came on

SOURCE: 2005 New Jetta and My EPC light

need to recalibrate the throttlebody

SOURCE: VW PASSAT 03 V6. EPC AND TRACTION LIGHT COME ON INTERMITTANTLY.

First, to read VW codes you will want to get yourself a $50 VAG tool. It will read all your systems, not just the ECU.
Electronic Power Control can go out for several reasons. Check your brake lights with the car running. Check you radiator fluid level. If the car is running bad, you could have bad spark plugs/ wires or ignition coil.
The traction control is tied into the ABS system and often causes problems here as well. Each wheel has a speed sensor and magnet wheel in the hub. You can check these for damage by removing the tires for access. The sensors come out by hand, and inside the hole they come out of is the place to check the magnets with a flash light. Apply a small amount of wheel bearing grease to the sensor.
The control unit goes out in these systems at an alarming rate. They can be easily removed, and repaired for under $200 at modulemaster.com
Since it is intermit, I suspect most likely a loose sensor, or electrical connector.
If your brakes feel squishy at all, bleed the brake lines of air and contaminants.
Good Luck!

SOURCE: 1999 vw golf 2.0 gti idle problems

get the crankshaft sensor checked out