Hey Guys,

Having some trouble with my 2006 C350 Sport with 149k.

Background:
For the past couple months I was having the classic intake manifold flap failure issue and had all the codes related to that. After installing a new intake manifold everything seemed to be working great, at least for a few weeks that is.

Now I am getting a bunch of codes and have no idea what is the root cause. After clearing the codes and starting fresh, I can drive for about 20-30 minutes before a pending code shows up. Keep in mind this is with a basic scan tool, I don't have anything specific for MB, I got the stuff for BMW (INPA/ISTA) and the VAG-COM for VW/Audi but no tricks for Benz. if there is a cable or software that I can get, let me know.

They show up in this order every 5-10 minutes.

First P2177 then a few minutes later P2179.
Then P2000 followed by P2003, P2248, P2244 and then ultimately the hard code sets off the Check Engine light and P0139 & P0159 get added to the bunch.

After the first couple codes show up, the rough idle begins and the exhaust smell is pretty bad from the initial start up. It still seems to run ok but when accelerating a puff of smoke comes out of the tailpipe. Also it is burning 1/4 tank of fuel over 40 miles (mostly freeway).

I have went back through the entire intake manifold procedure to verify everything is plugged in correctly and hooked up. I cleaned up all the connections and reseated all connectors. I didn't find anything that was unplugged or disconnected. I sprayed carb cleaner around the intake manifold and vacuum lines but did not get any evidence of leaks.

Not sure what I am missing here? Any advice would be greatly appreciated.

Thanks in advance

 

Just wanted to give an update on the repair. I ended up taking it to a local shop that has the Star software so they could perform a proper scan.

The diagnosis they came up with was the upstream O2 sensors were bad. I supplied them with the Bosch parts and went ahead and had them change them just in case their diagnosis was incorrect.
It has been a week and everything seems to be working correctly so I guess they were right. Fingers crossed that it solved once and for all.

Thanks again for all your help.

Cheers!