A class problems

[swansea v6]

My elderly next door neighbours have a Mercedes A class which has started giving them a few problems. They had the engine light come on one day last week and had a diagnostic run on it which flagged up lambda sensors, which they replaced but the light is still on? They then had it re-scanned and the same garage said the ECU is faulty and needs to be replaced at a cost of £700+!!
Now the car runs perfectly well except for it bogging down slightly at low revs (under 2000rpm) above this it seems to clear and revs nice and cleanly. As the car is only used for short journeys I took it in a nice long 'run' for them, using V power and a decent injector cleaner. The car now bigs down a lot less than before and is almost running 100%, could it just be the fact it needs a decent 'Italian tune up' now and again? Or could it be the MAF? can you do an ECU reset on one of these?

[richarda0109]

What is the model and year of the vehicle?

Rgds
Richard

[swansea v6]

Hi, it's a 1.4 litre and on a 'Y' reg

[richarda0109]

Ok so its an A140 w168

I will search that for you but I have personally moved on from a W168 to W169 shape vehicle
Can you scan the following page
http://www.aclassinfo.co.uk/mypage.1.htm
This is Loftys Page on the W168 - his knowledge of the 168 out strips mine
You can also email him if the answer isnt on his website


Regards
Richard

[swansea v6]

Thank you for the link, I will check it out. Disconnected the battery earlier today then took it for a long run once I had reconnected it, the light did not come on at first then returned.....

[s4avant]

Slightly different vehicle I know, but I had this problem on a 540i BMW.
After much fiddling around with oxygen sensors in the exhaust system, it turned out that the air mass meter was at fault. Once this was replaced the car ran perfectly.