'01 Jetta 1.8T idles rough when cold

Any assistance would be greatly appreciated. (1) Runs great when warm and warm outside. Below 45 degrees F, idles rough and stalls, will run well if you can get the engine warm. Do have a check engine light, but always have it...yeah I know...that ain't so good. But think caused by caltalytic converter going bad. Have not checked codes...brings me to second question (2) How can the common person check the computer codes?:banghead:

I have a similar problem and would be interested to know what the deal is. Also my transmission doesnt shift nicely when its cold.

You can buy a handheld code reader from your auto parts store or even walmart has them. The same thing happened to me the other day so I put the Stock air box back in, what I found out was that the battery i have isnt for very cold days and I live in florida so it usually isnt a problem. I suggest checking your throttle body to make sure it isnt grimed up cause that could be a problem to.

Higher mileage 1.8t (70K) have issues with the breather lines under the intake manifold and to the side that go the the valve cover and then the intake pipe on the driver side of engine. The lines get brittle and crack. If they need replacement replace all of them (about 10 total hoses with the brake pump) parts alone are about 500.00.

Driving with theese hoses broken cracked will also allow engine sludging