Originally Posted by TimFreeh

Did you ever get this problem resolved? If so what fixed it?

I have a very intermittent (like once every 3-4 weeks) P0410 that I'm chasing on a 2000 C230 Kompressor.

The strange thing is when I activate the air injection system for the first time the voltage on the pre cat O2 sensor drops to around 80-100 mv and seems to hang there. If I repeat the test a few seconds later the voltage drops like a stone to 20-30mv and remains there for the duration of the test and all subsequent activations during the diagnostic session. If I wait 15-20 minutes and repeat the process I get the same initial pattern - first activation "hangs" at 80-100mv with subsequent activations at 20-30mv.

I thought maybe I had a lazy 02 sensor on my hands but after looking at voltage output on the scope the waveform and response time are perfect - is it possible to have a lazy sensor in an extreme lean condition that performs well in normal operation?

Any leads/insight appreciated.

Tim