Hi there.

The warning Testing engine electronics light comes on my 2004 1.8t Vrs, it sometimes stays on for a week then goes out, i can then go another week with no light before it comes on again.When starting from cold sometimes it struggles to tick over until i give it a rev then everything is fine.

My question is, is it likely the light keeps coming on because of the poor running and if so does anyone have any ideas what might be causing it.

http://briskoda.net/octavia-i/help-my-epc-emissions-cel-check-engine-lamp/149217/

HTH

p.s. it could be you're temperature sensor, but it will need a scan too be sure