I helped a friend by jump starting her car - dead battery so it took many tries. Now my check engine light is on and the truck feels like it has bad wires and runs real rough when cold. First the light blinked 5 times - now it's just on steady. Where do I start with this one?

 

Start by getting your code read?

 

I had it checked last week for another problem and the tech said that the history showed multiple missfires. Maybe plugs and wires? they ARE old.
'99 3.0 168,000 miles might be original wires; been a long time since plug change, too.