The check engine electronics light warning displayed with the CEL light on. I also lost all turbo boost - it was like driving my old '96 E300 - real slow and revved high. Then after some driving it was fine.

Even though the filter looked clean, it did seem to have a little more resistance than the new one.

It seems that the atmospheric line attached to the filter caused the vacuum transducer to read outside of range. It would clear up though - and only happened on colder days after a cold start, always overnight. Then it would be fine.

When I swapped transducers, the problem didn't change and it should have.

So, I replaced the filter on both vacuum transducers and haven't had it yet. I won't call it done because I am superstitious and I need to prove it in more cold weather that we haven't had.....