Want to buy one and I want to know what traditional problems this car may have

It is a traditional F150 4.6 v8 and the code you are getting is P1549. This site will tell you a little more about the problem.Looks like they will need a scanner to properly diagnose which sensor may be bad.

https://www.engine-codes.com/p1549.html

need more info (need to know what type of ignition system your vehicle has: (1) traditional ignition coil /distributor system, or (2) electronic ignition, but lack of spark problems are usually a faulty coil
on traditional vehicles, and on the newer electronic ignition cars, total lack of spark would be
a faulty ECM (electronic control module) - partial lack of spark (diagnosed with a HEI (high energy ignition) spark tester kit), would be caused by a faulty coil pack (in the waste spark system), where
there's 1 coil pack for every 2 spark plugs.
I bought my HEI igntion testere kit for $20, but Harbor Freight sells a similar unit for $10.
Hope this helps.

you should go with the om stats, anything else would be a mistake

buy platinum plugs and u wont have to worry about gapping them...