Sick of this! Fixed my power/mileage loss, and then it comes BACK
 

97 c230.....cleaned MAF, MAF has 60k on it 2 years after replacement. Car has 163k miles. Power and mileage came back 100% within 4 days of cleaning, and then a couple days ago I was under WOT from a stop and somewhere about 4000rpm, 1st gear, I felt a stumble. Power and mileage immediately back in the toilet. Like I hit a brick wall.

What gives?

Its a Benz. They need a lot of maintenance.

And mine gets more than it's fair share of love.

Any sugestions? MBDOC?

Most likely a mass air flow sensor failure.

Cleaning rarely fixes the sensor, only a temporary condition.

Doc, you confirmed what my subconscious musings were trying to ignore.

A bit frustrating to only get 2 years out of the thing though.

I cleaned my MAF once and it only worked well for a few days before the stumble and poor mileage returned. I bought a new one and the problems were gone completely. I think cleaning just gives you a 50/50 chance of resolving the issue. In many cases you end up buying a new one anyway.

It's alright, just keep the old one in the trunk as a spare - they do occasionally go out completely, in which case your faulty sensor is better than none at all...