MAF sensor contributing to poor fuel consumption?

[Locoshaz]

Hi guys,

Quick question, if my MAF sensor needed replacing, would it contribute to poor fuel consumption? I have a 2001 CLK 200K and from what i've read in previous threads, i think the MAF sensor may need replacing. The annoying problem i have is that when the car is at lights or in traffic, it shakes very slightly. I think a cylinder or two is misfiring. Although it's quick, i feel that it's not performing as well as it could top end. It cruises to around 90-100, then it's kinda hard to get any more out of it. I think i've taken it to around 115mph (private roads of course ). I was under the impression that these Mercs could cruise easily at around 120. I don't drive it hard around town and i don't think i get more than 120 miles out of £20!

Anyone have any answers or suggestions?

Cheers,

LS.

 

[Uncle Benz]

You really need a diagnostic session to check for fault codes, but in my experience, the slight vibration/miss at lights when warm is often a lambda sensor fault.

 

[jberks]

£20 is only 4 gallons these days. 120 miles to 4 gallons is 30mpg. ANY merc other than maybe a C220cdi round town is doing well to return 30 so I don't think you have an economy problem.

Yes it could well be the MAS. If in doubt, get a diagnostic or just replace it. Its always hard to tell on a forum but Yes it should accelerate over 100 fairly easily and should cruise pretty much flat out, though its only a 1.8 (or 2l?) so I wouldn't expect fireworks.

I haven't seen a MAS cause a misfire particularly so a diagnostic is probably the best way to go.

 

[veedweeb]

I had the MAF replaced on my C240 about a month ago. It cured a lot of problems (dodgy gear changes etc) so it was definitely faulty.

After it was replaced, the car still didn't feel quite right, so I had a diagnostic test and that revealed 2 of the lambda sensors had failed too. Just waiting to get it booked in at the garage for them to be replaced under warranty.

Mine is not terribly smooth at tickover either.