my passat wagon with 80K miles has the “check engine” light come on (not blinking) intermittently. Sometime it stays on, sometimes not. Sometimes days separate the incidents. Engine seems to run fine. Mechanic “thinks” I might need a new $350 cam sensor switch. Help!!!

That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code (like P0123) not just their translation into English and post it back here.

Regarding warning lights:

  1. if the coolant temp light comes on, shut off the engine ASAP

  2. if the oil warning light comes on, shut off the engine ASAP

  3. if a FLASHING MIL/CEL comes on, shut off the engine ASAP

    ASAP means driving to the berm of the highway right now and not waiting for the next exit.

But if the MIL/CEL is not flashing, then it’s not an urgent indicator.

A flashing CEL means a miss-fire which is potentially dumping enough fuel into the exhaust that the cat converter might be damaged, but you can, and should, take it to a safe place to stop, not the side of the highway.