sounds to me like the directional contactors are worn out, dirty tips maybe
put tip kit in them or replace contactors

but by all means DO run the accelerator test in onboard diagnostics to verify that all the steps in the accelerator are working correctly.

pull the drive fuse
turn on key
put run/diag switch on card into diag mode
it will show d on display
then cycle switch to run test, each test you have to do in order it looks for so u need diagnostic sheet to tell you which one is which when it asks.
there should be a schematic under hood showing you panel diagram and will also have diagnostic routine on this, if it's gone then you need to get the manual.

as you run each test it will advance to next test if it passes.

keep cycling till it get to accelerator test and if it pass then accelerator is ok.
i'll look and see if i have this diagram and may can send it to you to help you if you need it now.

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