Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Check engine light on and rough idle 2003 Mazda Protoge

Today I went to the gas station and after I gased up and turned the car on my car started idling rough, almost to the point of cutting out. I started out on the road and my check engine light started blinking. After some time it stopped and just stayed on. The whole front end shakes pretty bad when at idle. The car has trouble accelerating till roughly 35-40 mph then seems to ride ok. I’m not very car knowledgable, but I do take care of my car. I know I need to replace some of my hoses and spark plugs soon, but am worried that it may be more serious. What I would like to know is: 1. What could possibly cause these issues and 2. Is any of the work needed something somone like myself can fix? Thank you for your time.


The fix could be as simple as replacing the spark plugs, but without knowing the stored trouble codes, nobody can tell you from afar. You need to get the trouble codes read immediately, as a blinking/flashing CEL indicates that the engine is misfiring, and continuing to drive the car in this condition will lead to much more expensive problems–like damaging the very expensive catalytic converter.

Can you fix it yourself?
Do you own a good set of tools?
Do you have good mechanical aptitude?
Are you good at diagnosis after finding out what trouble codes are present?

With all due respect, the fact that you admit to being, “not very car knowledgeable”, makes me wonder whether this is within your ability to fix on your own. I would advise getting the car to a well-reputed independent mechanic today, and not driving it any further.

A blinking CEL means a serious problem and most owner’s manuals say the car should not be driven at all with a blinking CEL. I think this is something you’ll need a pro to diagnose and fix.