I have a 03 Lincoln Towncar Limo with 110,000 miles that started running rough the other day. It hesitates when accelerating. The check engine light came on and it had 3 codes. Misfire on cyl 1, Misfire on cyl 6 and some mass airflow sensor code. I changed all the spark plugs with OEM Motorcraft, ran fuel injector cleaner and changed the air and fuel filters. Its still hesitating but it dosent give any more codes. Any suggestions?

 

Clean the MAF and reset the computer (either with a scanner or by removing the batt terminals for a few minutes).

I assume the CEL was blinking when you noticed it, does it still feel like it's hesitating as much right now?

Also, if you reset the computer, it will have to relearn the fuel maps and such.

 

Apparently if your Differential Feedback Sensor for your EGR (DPFE) has gone bad it can cause your EGR to lean out your engine causing a hesitation. Its incredibly easy to replace and might be worth a try. There are some threads on here talking about that, give it a search.

 

When I changed the spark plugs it was running better but after the engine warmed up (its 20 degrees outside) and driving about 1/2 hour it started to hesitate during acceleration again. This time its not as consistant as it was before.

I will clean the MAF sensor today and see if that works. The car has 110,000 miles. Do you think I should change the coil packs?