98 F-150 4.6L V8, 58K miles. Just thought i go by the book and start doing service for 60,000 miles. Truck running fine, replaced plugs. Now running rough and check engine light blinking? Feels like only 7 cyl. fire? It's not like the old days.

 

It is not totally unheard of to get a bad plug from new. I have also heard of the same trouble with Bosch plugs.

First thing I would do is check all electrical connections.

 

I got a 97 with 4.2 V6. I changed my plugs and the engine was hesitating, and missing. I changed out the wires a fwe days later and everything is fine! Try some new wires. I got Bousch wires, they're already sized with boots. Its not too hard, just stay patient. Good luck. For a V6 the wire set was about 58 from autozone.