sfury63

So I picked up an 09 c63 from carmax and it ran beautifully but like all things, I wanted more power. First mod i did of course is to remove the charcoal filters. What I discovered was I only had a charcoal filter in the left airbox. I thought nothing of it really and disregarded it.

Wanting to do more, i pulled the trigger a few days later and got a Eurocharged tune. The car was a beast and I couldnt be happier. Well within a few days, I got the dreaded P0171 (Lean - bank 1) cel.

Fortunately, I had my own obd2 scanner so i elected to just clear it. Well the stubborn cel kept coming back after about 50 miles of driving. I also took notice of it that it always occurred minutes after pulling off the freeway.

I took the approach of troubleshooting everything by process of elimination in the course of 3 weekends.
Re-tune back to stock - no luck
Restoring the charcoal filter - no luck, same cel.
Replaced with new air filters - same cel
Cleaned both MAF - same cel
Smoke test for any leaks - no dice/no leaks discovered

After doing some more reading, I came across another fellow mbworld'er who had mention he discovered having only one charcoal filter in his c63. Now at this point, I was considering just replacing the whole intake airboxes just to rule out. All the while, I came across some thread on the row airboxes and to my surprise, they were identical to the right airbox I had.

It had me thinking and of course I go back to examine both knowing now what the ROW vs US looked like. So now heres my weird setup, my right box is a ROW and the left, a US airbox. Has anyone ever come across this?

Anyways, I ordered a ROW box for the left (might as well since I already have one) and Im hoping this will do away with the stubborn p0171 cel.

Thanks for the ear everyone, just wanted to share what has been haunting me for the past month……


Update: 1/26/2013
Update: So i ended up getting a row box for the other side and drove for about 250 miles at which point my guess is the ECU adapted and the CEL disappeared on its own.

But the story doesnt end there.....Just two weeks ago I had the damn headbolt/coolant issue hit me......
https://mbworld.org/forums/c63-amg-w...ant-issue.html

Merc63

Intake manifold of faulty purge valve off the fuel tank.

Also make sure there is no leaks past the metal clamp that secures those boxes to the intake, as they are after the MAF sensors.

You have air in the system after the MAF.

Jons95c36amg

I had this annoying Cel code-P0171 too before with the old tune without the charcoals. Now with the new OE tune no more annoying lights.

_timothy

did swapping out the other box for a ROW fix it? i just bought a L/R ROW and am installing soon

L8brker

I had this exact same thing , I thought it was the filters/ row airbox
IT IS NOT THE FILTERS OR THE AIRBOX I took it to Mercedes and it was a manifold leak , they can test for it they replaced the manifold bolts with new ones and new gaskets ,re test and perfect. been driving fine now with no cel for many thousands of KLm

L8brker

On a side note you should have the same airbox side to side ,that's just weird
So put either us/ row , just make sure there the same

Ps I have afe pro dry filters they kick ***

sfury63

Update: So i ended up getting a row box for the other side and drove for about 250 miles at which point my guess is the ECU adapted and the CEL disappeared on its own.

But the story doesnt end there.....Just two weeks ago I had the damn headbolt/coolant issue hit me......