08 versa with 1.8l barely goes, acts like gas pedal not connected.

What is your question?

every other time i go to take off, it just barely moves in forward or reverse. acts like gas pedal isn't hooked up. turn key off and start again and it will take off like nothings wrong put it in neutral and revs right up other times rpms just barely go up. any ideas out there whats going on with it? Had 420 code come on about a week ago hasn't come back on since.