Yet another CIS lambda question - PeachParts Mercedes-Benz Forum

fahrgewehr2 · #1 02-10-2004, 05:58 PM

(300SE)

Car runs great except for about 30 seconds- one minute, when the car is around 60 degrees C. During this time the car will surge and act as if I am taking my foot on and off the gas. During this time the car is switching over to closed loop operation as I can see the mixture begin to fluctuate.

Its not a big problem as it only happens for a short time and is predictable behaviour.

I suppose I could just live with it, but that would be too easy.

What do the experts think?

fahrgewehr2 · #2 02-11-2004, 11:23 PM

Anyone have an idea?

dyazdani · #3 02-16-2004, 09:03 AM

My C230 has a similar issue. I had a CE light with the P0170 (I think) code. Searched the forum to find that most of the time it's the AMM. I swapped it out yesterday, no change. I'm not sure where to go next.

fahrgewehr2 · #4 02-16-2004, 05:45 PM

I'm guessing something is happening when the o2 sendor begins to send signal. Like the system is in lambda limbo

I was thinking maybe a coolant temperature sensor was giving off a weak signal?

We use different systems, but the underlying idea between the two must be similar?

dyazdani · #5 02-16-2004, 06:07 PM

I replaced the AMM, when I started the car back up (after disconnecting the battery to get rid of the CE light) it ran rough like you described. The CE light came back on a while later with codes 0300, 0301, 0302 mis fire. I'll have to check into that more.