Sounds like the OP has an issue with stalling. A TPS might help solve that, a GS911 is not needed for that. It could be the idle bypass controllers being out of synch, a GS911 can reset those.
It could be one or more of a few other things. In no particular order:
A coil breaking down.
A trapped throttle cable.
Bad spark plug (s).
Someone adjusting the factor set throttle stops.
Valve clearances way out.
I would go the easy one of checking the cables, especially the rightbhadone Then do the standard TPS reset procedure; check the valve clearances and if you have GS911 reset the idle bypass adaptation.
Sent from my SM-G388F using Tapatalk