Mazda Misfires

Hello! I have a 2002 Mazda Protege’ which recently started losing power periodically. At the same time, the check engine light would blink and then stay solid. The dealer diagnosed a random engine misfire and replaced the spark plugs, wires, and coil packs. It cost $500.00. After 3000 miles, the problem has returned worse than before. This weekend it lost and regained power repeatedly in short spans of time, and lurched back and forth as it happened. The check engine light returned as well.

My first question: what do you think this is? My neighbor suspects a clogged fuel filter or fuel regulator.
My second question: what, if anything, does the dealer owe me financially?

Thank you for your consideration.

The vehicle needs to be scanned again to find out why the Check Engine light is on.

What does the dealer owe you? Nothing. They repaired the vehicle and you drove it for 3,000 troulblefree miles. The problem the vehicle is having may be a whole new issue.



You need to be methodical
Post fault codes

If it’s a misfire . . .

Compression test
Fuel pressure test
Check for good spark at all 4 cylinders

IMO the cause of the misfire (if that’s what it is) needs to be thoroughly diagnosed before replacing more parts