1999 ML430 with 91K.

The vehicle set a code last night, P0173-Fuel trim malfunction (Bank 2). The vehicle idles and runs fine and no other codes were set. Any ideas??? MAF sensor? Dirty air filter (looks pretty dirty)?

 

No comments???

I replaced the air filter, which was dusty, but not as bad I as I thought. I reset the code and it has not returned so far. I would still like to find out what caused it. I do suspect it will return. Any help would be appreciated!

Thanks!

 

New guy here. I had the same problem awhile back with same code. Did same thing you did. New filter and erased code. Came back about a week later with both banks malfunction. I guess as the maf gets worse it will run rich. Replaced maf with new one, took about five minutes. Price about $285, fixed it right up. Good luck!

 

Thanks for the reply!

It's been a couple of days now and no CEL. I'm keeping my fingers crossed, so I don't have to part with that kind of dough!