Check Engine rough idle issue...
 

Hey guys i just bought a 2006 CLK500 Cab for the wife 2 weeks ago, drove the car home 300 miles with the top down (nice feeling) after a few days dropped it off to my buddy to get the car detailed and install some tints, when i went to pick the car up from him i received a Red Batter Lights on the dash and after a few minutes the car died, so ended up putting a new Bosch Alternator and AGM Battery, drove the car home (15 miles) and drove wonderful, after a few days i start the car to go buy a few things and the car started acting up and almost shut off on me, so i drove it home (limp mode) and as i got home the check engine popped up, i scanned the car and came with one Code P0104 which is a code for Mass Air Flow Sensor, so i ordered a new Bosch unit replaced it yesterday and same issue again, idles funny the exhaust smells like its running rich and same code, anyone have any ideas? Plugs and wires look good and when i bought the car drove it for over 300 miles with no issues at all.

Thanks

Where did you get the Bosch MAF sensor? If from Amazon or eBay, it; probably a fake.

Maybe get it scanned with a STAR diagnostic tool if you haven't already? That may or may not provide some additional info.

Otherwise, I don't really see anyway around getting it diagnosed by an independent specialist who can do some troubleshooting (unless you have the time and skill to do it yourself).

I've had a very slight rough idle (barely noticeable, but I can tell something is not entirely perfect) in my 550 since i bought it a couple of months ago. My (very experienced) local Mercedes guy couldn't figure it out after doing a bunch of diagnostics.

In any case, best of luck!

Crank position sensor? MAF sensor? Last year I had a rough idle that progressed to the car stalling (81K mi). It was the crank position sensor. Also make sure you have a good seal at air cleaner and MAF.

thanks i have a friend of mine who is going to stop by today and take a look at it, i was going to do a Trans Flush next week so i was going to change the Crank Sensor regardless.even tough i doubt this is my current issue

Did your car generate any codes when this happened?

As noted above, I have a barely-noticeable rough idle, but I want to solve it before it gets worse since this is my daily driver.