Don't know what to do
 

My vehicle is doing the same thing. It is surging without pushing the gas. The code that popped up is P061b. I have spoke to some people and they think it could be the throttle control sensor. Any ideas?

Some people have cleaned the throttle body inlet and butterfly and the problem disappeared. Its worth a try.

It is a known problem with the throttle body. SOmetimes cleaning helps but it will eventually need replaced.