I'm baffled too.

 

Been mixing 99 with excellium for 4 months what am doing to my car

 

Check your fuel filler cap is on properly if you had just filled up

 

Never put jam on a magnet.

 

I work on the momentary lapse of reason principle;

pull the battery or fuse & if the CEL doesn't re-appear, it had a brainstorm. Or some absent-minded twat forgot to reconnect a sensor whilst cleaning his plenum chamber, which has happened. :embarrassed:

 

Well, it turned out to be an oxygen sensor, so well done to DannyG for suggesting that. My experience was exactly the same - they reset it, but about 10 miles later it was back on. They didn't have any in stock (surprise), so I thought I'd kill two birds with one stone and booked the car in for its first service whilst the sensor was getting fitted. They used 0/30 oil, has this been other people's experience?

 

Anyone was guessign until you got the code.

Regarding oil - see the FAQ sticky thread. 0W 30 wouldn't be my personal choice.

It is a bit worrying the amount of brand new cars which are having lambda probs!

Glad its sorted.