well leaks don't get better on their own and depending on whats leaking it could cause additional damage, but just saying that its a ball bearing is not specific enough to even guess at what the issue could be going to need more info than that
not necessarily, I had codes 24 25 and replaced the o2 sensors and still had the misfire. there was corrosion in the connector that was an additional issue. replaced the connectors and problem solved, for now
because you want the relay on the power side for load control and these are 12v negative ground systems. its better to run higher current through a relay and have something that is a lower current turn the relay on and off
you could always go to a shop and have them make you an exhaust pipe and fix other leaks in the pipe while their there.
ya looked again and I totally misread that as header pipe not heater. still too early with out enough coffee in me
that's actually a reasonable price from the dealer for the miles and condition, they would just send the truck out to wholesale.
unless your dad authorized tare down time theres no way that they would be looking at the head gaskets. get it taken somewhere else and get a second opinion or do...