I still have no codes and this morning every couple minutes at a stop it would hesitate and shake and wouldn't move for a couple seconds then bam full power and gone. Could this be a fuel issue?

 

First you said no CEL, now you say no codes. Have you actually plugged in a code reader to interrogate the system? If not that is the first place to start.

Did you change the air filters or did you have that done at the dealer? It's possible you don't have something back together quite right, that's easy to mess up that seal at the back to the intake pipe.

Good luck.

 

No check engine light on still but I have a code that won't go away which is P20D4. Also I popped the airbox on top of the manifold and just whacked it down. So that could be an issue. How are you supposed to properly put it back on?

 

No check engine light on still but I have a code that won't go away which is P20D4. Also I popped the airbox on top of the manifold and just whacked it down. So that could be an issue. How are you supposed to properly put it back on?

As to DTC P20D4, read this post from MBWorld which suggests that you may indeed have a MAF issue item #665 or gasket #612 shown below.

Also in the WIS instructions for the R&I of the crankshaft position sensor, we are instructed to lube the seal and rubber mounts on the Air Filter Cover, (wonder how many of us have overlooked this step when removing the cover??)

Hopefully the issue is the seal and you can just clear the code and move on.

Close out this thread with your success story.

Good Luck,

Bob

 

Thanks, I had replaced the MAF and all is good now.

 

I have a 2006 S430. After it warms up it starts to rough idle and starts shaking. I have no codes or check engine light. I have changed all 16 plugs and wires, changed the mass air flow senser, the map senser. All the vacuum lines were changed. New air filters, just can’t seem to figure out what is causing this issue. If anyone has any insight, please let me know! I’m a Honda guy, never had a MB, got a good deal on this car thinking it would be a simple fix but it’s gettinf the best of me! Thanks!

 

Anyone ever figure out what was causing the rough idle?

 

Thanks, I had replaced the MAF and all is good now.