new problem, exhaust maybe?
So, this truck's been trouble free for a couple years now. Today doing about 60mph when letting off the throttle I get a brief resonance, sounds like low groan, lasting 1/4 second maybe. Back on the throttle and it happens briefly again. When at speed nothing. When doing about 40, hardly noticeable.
After I stop, rev the motor, let off it and there's a "pop" at the exhaust Not a misfire just a "burp" really. I don't recall having that before so I'm thinking exhaust leak