Yet another CIS lambda question
 

(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?

Anyone have an idea?

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.

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?

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.