miss fires bucks at highway speeds when trying to speed up or up bridge

Have it checked for misfire codes,,you got one!!

Need to have scanned for codes. Can get a free read at autozone then post result. Probably a misfire condition or exhaust flow issue.

what I found is the timing chain cassets wear over time and the slack in the timing chain causes the mis fire on cyl 1&2 between 1500 to 2400 rpm at a slight load.