check engine light keeps coming on....after repeated starts, it goes out until the next time. Started noticing it in the winter months , but now it occurs irregardless of the weather/temp. 50% of the time I notice a lag in power, then as I suspect the light comes on. It doesn't seem to affect mileage, and the momentary lapse in power is only a couple secs...My mechanic (only services volvo, but not a dealer) tells me it's like a witch hunt--if I want to spend alot of money, he may be able to find the origin and repair it. In the meantime, he says not to worry about it.....but it is not normal, and should not be. I suggested to him it might be a bad O2 sensor, or something....he strongly doubts that. 2 years ago, I had trouble with the EGR (?-forget, though I could look it up in paperwork I saved)---he got rid of that red engine light with (finally) a satellite computer download from Volvo, when everything else failed he suggested (and after about $3000)

 

What's the code? Sounds like your mechanic isn't very good.