I've been getting the same problem for a while now. I have a 2002 Audi A4
Quattro 1.8T manual transmission.
When I go on a road trip I usuall pull over after two to three hours for the
first pit stop. (all highway driving for at 120 kph constant) After I am
done my stop, after I accelerate out back to the highway the check engine
light goes on after a few minutes and will stay on a for a day or two even
after the road trip is finished before turning off. This has happened the
last 5 out of 6 journeys. I see no changes in fuel economy or the temp
guages so I am wondering what kind of sensor problem it might be. I never
get the check engine light on shorter trips of normal driving of up to 30
minutes in the city/highway driving. At first I though it was bad gas (which
has happenned a couple times it seems) but it happens even when I don't fill
And Ideas what it might be. I don't have a code reader. I will have it
checked when I take the car in, but its always night to get some ideas.