Hey scotty, I have a 2009 accent with about 90,000 miles and it is a manual transmission.
Whenever I go up hill or goes under load when passing it starts to shutter sputter and shake.
It does it only after driving on the highway and turning on a exit or passing someone, it never throws a trouble code and it does not matter what gear I put it in because it will continue until make it up hill. What you check first for something like this?
Check the fuel pump pressure with an analogue gauge. When did you last change the fuel filter, clean the injectors, MAF sensor, etc?
Several months ago I had all the fluids changed when I bought it, all the filters replaced etc, it only does this after I drive on the highway for half an hour and the problem lessens after I stop briefly in-between destinations
You might also record a snapshot of live data while the problem is occurring to play back and analyze.
