I have been battling the check engine light for months now and now I have a new condition which might point to why it is on: Recently, it started pulsing or blinking at the rate of about every 3-4 seconds. Too, with the car in "drive", when I take off the car bumps and I notice that it affects the check engine light (it blinks) at the same time. If I start off in " 3" gear, the car doesn't bump but the check engine light pulses or blinks as I described earlier.