My son has a 2002 CRV with about 150K miles on it. It has run nicely for the past month (he got it used a month ago). he just noticed that when he is driving it at speed (say above 45 mph) and accelerates above 3500 rpm, the car appears to shudder and hesitate like it is not getting enough fuel. The check engine goes on. What questions should I be asking him to help identify what the problem is and how best to address it. Weather is in the 40s.