03'55AMG

Just now got back from a drive to the store and it rained quite hard while I was inside. Well on the way back I encountered a semi-flooded road, Enough water to touch the exhaust. Before going through it i raised the car then proceeded at about 3 or 4 MPH. Then after i got through it I knew the exhaust got soaked because of the massive amount of steam coming from under the car, and it didn't smell or look discolored, just steam. Well right when i was pulling away, the CEL came on and the car started acting like it was in comfort, even though it was in sport. nothing is making noises or anything, its just shifting supper early, starting off in 2nd, and throttle response is super slow, even though it clearly states 'S' in the cluster. switching through the modes did not help, except manual(acted normal, but still super slow throttle response). Any ideas?

Denroll

Did you try restarting it? Probably did something to the O2 sensors. How long did you drive it?

I've had weird things happen every now and then and a simple restart cures it right up.

03'55AMG

Restarted it twice now, even drove around more. The C/S/M problem is gone, but still have a CEL. the car is also very surgey, like when i let off the gas its like its hitting the brakes than gas then brakes then gas except really fast intervals... Really annoying

RedBullJnky

Let it dry then try and see if CEL goes away.

2008AMG63

This!

Something kind of similar, but more water involved, had to replace O2 sensors.

Blk04e55

Lets not forget about the transmission's electrical connector, its at the same level as your exhaust. When our transmissions throw a fault code the only way it can let the driver know is by turning on the CEL.

Im willing to bet if you scan the CEL it will say 'read out transmission fault codes ' You probably shorted something out in the tranny and most likely just needs to be cleared to run right again. Find a friend with a MB SDS scanner

shardul

iTrader: (1)

Let everything dry out.

benz_addict

read the codes, sounds like the car went into limp mode. Something to do with the TCM I bet

Firechaser

Let it rest and dry out for a day...you probably soaked a few sensors and the water is causing them to ground out or something....let her heal

03'55AMG

Cars completely dry, although still has the CEL. Drives great though except for the damn stumble. Ran over to autozone and the code showed a "very small vacuum leak in the emission system".. Wtf?? I believe the code was P0456. I remember it had a P04 something, want to say P0456

Firechaser

Drive it around, may clear on it's own. Glad to hear it's running for ya again.

Hasan Shaikh

Give it a nice blast to 200mph.

That should clear out the exhaust.

03'55AMG

The CEL went away a few days ago, but going threw a bigger size puddle tripped it again!! WTF? codes were P0456 and P0456. I know, same code, but both had 2 explanations. one says, "The ECM has detected a large leak in the EVAP system during a system monitor check" the other one reads, "The EMC has detected a very small leak in the EVAP system during a system Monitor check." Any Ideas?

The little receipt autozone gave me says it could be:
-defective, Loose or Missing gas cap (checked. All fine)
-EVAP canister broke, hose cracked or not connected (Dont even know where to begin)
- Purge or vent solenoid defective (Dont know where this is)
-Large vacuum leak at engine (This may be one of the codes, but I do have a bigger crack in a vent hose that looks to be running from one valve cover to the other. and upon putting my hand over the crack, the car idled a Lot better... Can't find a part number on the hose or in WIS. If this is simply a hose connecting to two barbs, wouldn't any hose that could take a little heat work?

Firechaser

Stop driving through lake-like puddles! Dry it out again

03'55AMG

I Didn't aim for the puddle or anything, they (puddles) were in the ruts from tires in my alley behind my garage. I also was not even going fast at all, maybe 10 or 11 MPH. this is weird.

Firechaser

Did you fix your vacuum leak? that alone will make any car run like poo-poo. if it's just vacuum line, any auto part store carries it.

03'55AMG

Found a part # and will be giving my local Mercedes a call here soon.