Check engine light came on....Code po301...Idles nice and runs fine sometimes but misses ocasionally and get a little back fire. Any Ideas where I should start?

Just bought the truck
1998 F150 4.6 engine
100000 miles...truck looks like new
spark plug wires have a 1998 number on them.....surely these are not the original wires or are they?

Any advice to what I need to start looking at? Very frustrated...just bought the truck and havent put 300 miles on it yet?

Help please?

Thanks
Bob

 

Misfire cylinder 1. If wires say 1998 those are the original wires. Start with a tune-up at 100k you are due for one.