Originally Posted by
sethb
2 hours seems like way more than enough time. It's less than a 15-minute walk from the area in T4 where you'll land to the SkyTrain, under 5 minutes to T1, then you just have to clear Security Theater again.
Or, take the bus from T4 to T2, exit and walk a short distance to T1, clear Security Theater again.
Do you need a valid BP for a connecting flight operating out of T2 in order to access the jitney? Long ago, you needed to show your BP before getting on the bus in order to show that you had a reason to be on the bus.