CHECK ENGINE - HELP

[JAKESANGEL]

Seems like something goes wrong with the old girl every month, this morning after putting  normal unleaded petrol in the car (Golf GTi 2.0cc 2001) the "CHECK" light with a picture of the engine (i think) came on. The light came up in yellow (not red). can anyone tell me what this means or do i have to pay a fortune to V.W. to give me a diagnostic report. Is there a cheaper option. Any advice is greatly appreciated, cheers. 

[toby211]

Had a similar problem (perhaps) with my 2.0l 8v.  Very occasionally when going along the engine management light used to come on and the car would kinda lose power then stall - sometimes with an emissions warning.  Could restart engine fine straight away and then wouldn't happen again for ages.
Turned out (when it went completely) to be a relay.  Something to do with the immobiliser I was told.  Cost like £15 to fix and has been spot on ever since.  Shame about the £75 i had to pay to get my Dub towed to a garage for them to diagnose it.
Failing this - there's a lot a people about who'll read your codes for a lot less than VW!
Hope this helps.

[Stu-1.8T]

The light came on in mine when i first got the car, but it was running a little bit rough because of the airflow sensor needed to be changed.

My wife's 2.0 was running fine and the light came on. We ignored it for a couple of months until it came up for the service and VW could'nt find anything wrong either and the light went out when they checked it.

Too many worrying light's in modern cars I reckon. If it drives o.k, and it's been serviced properly there should'nt be a major problem.

[JAKESANGEL]

Thanks for the responses guys, my mate took it to his pal last night who has the diagnostic equipment and apparantly the mk 4 is notorious for the the engine management light coming on !!!!!! (presumably more bunce money for V.W.) anyway the  error codes are as follows:

408b - 02 sensor (bank1, sensor2)  signal too slow
412c - combustion failure detected
412f - combustion failure cylinder 3 detected

Still dont understand the codes but they advised me to change the plugs and leads which im doing today. anyway the light has gone out  now so it doesnt seem too much to worry about but new plugs and leads can only help. Thanks again guys cos i was a bit worried but as you say too many lights on cars these days