PeachParts Mercedes-Benz Forum - View Single Post

EricSilver · #2 04-08-2009, 11:41 AM

The above is very, very good advice.

I went to clear my persistent clogged EGR code 5 on the DM when I saw there was also a code 2 (inoperative Heated O2 Sensor). For the past few weeks I have experienced somewhat sluggish acceleration, somewhat erratic idle, and very noticeable pungent exhaust fumes.

Upon pulling back the carpet I saw a very small amount of water in footwell. But when I squeezed the insulation/padding, it was like squeezing a wet sponge. I also saw that the three-wire connector(s) for the O2 sensor was green with corrosion, the second white wire from the gray one being the originating point.

After thoroughly cleaning the connectors and reattaching, the erratic idle is gone (the dashboard looks like a photograph because the tach and oil pressure gauges don’t move); and acceleration is crisp again, whereas before it was kind of mushy/sluggish, like walking in slush. The fumes, however, though not as bad as they were a few days ago, are nonetheless still present, which directs me to replace the coolant temp sensor which I know is faulty. (Now I know why I’ve had daily headaches for the past month or so.)

It appears, however, the insulated floor mat, which is now sitting out in the sun, will take a few days to dry out. The water came in as described in the previous post, in a small trickle, except my entry point was where the cables/wires come through the firewall. windshield drains are clear, but the rubber guard piece at between the glass and the edge of the hood was somehow twisted out of place. It does not appear to be a heater core leak as there is nowhere near enough coolant loss to account for the amount of water in the padding – unless this has been going on and on for months, with the padding never drying out. But after running the heater, I saw no water leakage.