I was resetting the lambda today on my 92 190E2.6 after a good cleaning of the sensor plate and throttle body. As I usually do once a year, I check and clear the codes int the engine computer. Every time over the last several years, I have always noticed error codes for the EGR and Air Pump. The MB dignostic manual only states that the codes are (11 & 16) are EGR and Air pump. I know that both are functioning when I check them but was wondering what the computer is looking at to determine these errors. As far as I can tell, the only electrical thing I can see are the vaccume solenoids and Air pump clutch. I have changed the OVP relay within the last year due to the ABS light comming on. Any ideas are welcome.

Thanks
Rod

The computer checks with the O2 sensor at different times to be sure that these are operational. There are very specific times that it does these checks.

A vacuum line that has a pinhole is the most likely cause in this case.

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