I have a 2000 Taurs with a 24V DOHC 140,000 Miles. Runs fine except at idle. Car will idle fine, in gear and out, for a minute, then the check engine light starts blinking and the engine runs like two spark plug wires have been crossed. After about a minute it smooths out and the check engine line burns steady. Had it checked by the dealer and he said I needed a new HPDE (?) sensor and a new engine because he "thought" I had a burned valve. I replace the plugs and the sensor and the car did fine for a week and then started this all over. Replaced the sensor again, and it cleared up for a day. Check engine line stays on. I have a hard time believing that I have a burned valve because the condition is intermittent.

 

What is the trouble code that is stored in the computer? You can go to a major parts chain and they will read the codes for free. Please post the exact number, not a definition. It will be like P0302 or some other combination of numbers. That will give us a place to start.