I’ll try swapping coils and clearing. I’ll also knock on the cats. It’s not wanting to shift right either. Doesn’t shift into overdrive on highway.

 

hmmm.
Could still be ignition related

 

Swapped the suspected bad coil to cylinder 2 and took it for a 10 minute test drive/ power brake session. Not even enough power to turn over the rear tires but no codes, pending or otherwise. No abnormal noise from the cats when I wrapped them with a hammer.

 

Does it bog down any?any abnormal sounds? I'm wondering if the timing is shot...

 

No no bogging down. It literally feels like it’s running and idling just fine but I have a 5000# trailer attached to the back.

 

Maybe something's wrong with the transmission? You do have 150,000 miles on the truck.

 

That’s what I initially thought but then I get a fault code for a coil.

 

Have you ever done a transmission fluid change?

 

No. Fluid doesn’t smell burnt. Doesn’t look cherry red, but it doesn’t look terrible. Also, trans temps are reading about normal and the actual quality of the shift isn’t effected.

 

Personally I’d look at ignition sources, not transmission. Maintained a transmission will outlast the frame on these trucks.

Have you ever replaced the fuel filter? Apologies if you’ve already stated... I’m in the airport and following my tradition and don’t recall if you did.