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Q: What would cause a random misfire when driving at highway speed on 1999 Chevrolet S10

Rookie cbe0621eac06868b3efe0d8d1d3611e23c60d3114864ea2ec19a68cfbd3eebab
Runs strong in town and sitting idiol but when u get to highway speed it runs a little rough and throws a random misfire code and hills on the highway it does it more and looses a little speed. In town it is really strong and does not send the code hill or no hill I have changed plugs , wires it has all the power and runs Awsome until u get on the highway
(1) Answer
Good scanner and a mechanic can run a 'movie' to view later for related problems. Also can check freeze frame data, just dont attempt to erase codes before test. Most likely ignition breakdown, more pronounced in higher gears, more load on ignition with lower rpm on highway.
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