only starts after sit awhile, p0122,p0181,p0431 showing

Question

sometimes driving rpm go down but not stop

Answer 1

P0122 Throttle position sensor circuit / range performance problem

P0181 Fuel temperature / coolant temperature

P0431 Main catalytic Bank 2

Will start when the temperature goes down, this is where the cooling system has to be check , low fluid in the radiator whether you use water or coolant check for any leaks causing it to low, P0122 This could be just a performance problem due to the engine temperature , If engine temperature there is no overheating situation. The TPS sensor would be the correct repair to resolve the situation,