Not sure what help you need! You seem to have found the culprit already!

There may be other faults as well, but fit a new air flow sensor, clear the alarms and see what, if anything, pops up afterwards.

 

I'm pretty sure that when you disconnect the MAF the car reverts to a " Standard " setup , so I'd say it's quite possible that you have a faulty MAF .
I've read that a lot of the cheaper MAFs available tend to give quite a lot of problems ....

 

I agree... You can try cleaning it, bit if its oily you should find out why. If it's not only just replace it. I'd use MB or Bosch branded.

 

Whatever you do don't get one of those cheap ones that you see for $50 on line. Bosch or MB only. Got a Bosch for a great price on Eeuroparts.

 

Welcome to SLKWorld.com: The #1 Mercedes-Benz SLK Forum from Valrico, Florida!

Your 1st thread should be your introduction so we can welcome you properly so post an introduction in the ‘New members introduce yourself here’ section, if you haven’t already. New Members Introduce Yourself Here - Mercedes Benz SLK Forum

Some tips to make your visit here more enjoyable:
If you haven’t, please use the 'search' feature at the top right of the page for your questions as they have probably been asked before. Remember, ‘Search’ is your friend.
If you wish to become PM (Private Message) capable, you need 15 posts. To get those 15 posts quickly, just go to the ‘New members introduce yourself here’ section and welcome enough new members to obtain your needed posts to PM.
Want to post a picture? Start a new thread or make a post, click ‘edit’, click on the ‘paper clip’ or ‘advanced’ and/or ‘manage attachments’ then ‘choose file’ then ‘upload’ and ‘submit’! If Iphone pics, you need to rename any additional pics as Iphone names its pics all the same, image.jpg.
Want to ‘like’ or thank’ someone’s comments? Use the ‘like’ button to the right or the ‘Thanks’ button, bottom right of any post you like. This saves you having to comment.
New members should be aware that the 'New Posts' link next to the 'Search' link top right of the info bar is a great way to see all of the posts you have missed since you were on the forum last. Remember to click 'mark forums read' under ‘quick links’ when you leave.
Post your vin in the Vehicle Datacard Request section to get a free datacard (options on your car). You must update your profile with vehicle info and your location and post an introduction first.
Also vote or enter our Ride of the Month competition: ROTM Submissions & Voting - Mercedes Benz SLK Forum

Thank you
Jeff
Moderator/Founding Member/Ride of the Month Coordinator