"Well there's your problem, lady."Funny you say that. I didn't know it was throwing a code. P00b7 which is "Insufficient coolant flow."
That said, how is it measuring flow? I wonder what the set criteria is for that code. Subaru will look for a temp drop after triggering the fans, and if it doesn't then the ECM determines the fans aren't working.
The above isn't apples to apples but if the Sonic is just looking for temperature drop it seems many overheat conditions could trigger it? I'm only guessing there's not an actual flow meter?