My 2002 Avant 1.8T was just serviced 2 weeks ago and has been running great. However, its been very cold here in NYC and just now when I went to start my car and move it to another parking space, the CEL came on at start-up and a hard idle resulted in an immediate stall.

I can keep the car from stalling by riding the gas a bit, but as soon as I get off the accelerator, the hard idle starts again and results in a stall out.

Could this strictly be a cold weather issue? A gasoline octane issue (I can only afford to put i regular unleaded)? Some other common issue? It's pretty frustrating. Any insight would be very much appreciated. Thanks everyone!

Chase