If I have predator and Howlrunner effects on a roll can I use both effects to reroll different dice? I'm sure the answer is no but was looking for the example in the FAQ and didn't see it.

There's no example but the rules state that dice can only be rerolled once. If you roll blanks on a two dice attack on a ship and predator allows you to reroll one die, Howlrunner will let you reroll the other one. If predator allows a two dice reroll, then Howlrunner's ability would not kick in.

As stone face says, each individual die can be rerolled one, but multiple effects can provide as many rerolls as you want as long as you don't violate that rule.

So howlrunner combined with predator on a nearby tie would allow you to completely reroll a 3 die attack.

You can only reroll a given die once but can use any number of attack modifications that would have you reroll dice.

The crazy example: Han Solo w/ Predator and a TL on a target may:

1. Use Han first which rerolls all dice leaving other two unused.

2. Use Predator first leaving some dice alone. May then use Han or spend TL.

3. Use TL to reroll any number of dice. If there are then dice that were NOT rerolled Predator may be used or Han's ability may be used.

In this example you could use Predator or the TL to reroll some number of dice. Han's ability could also be used but because it rerolls all dice available to reroll you could not follow up with Predator although I guess you could spend the TL to roll zero dice.