engine pining on 2006 Nissan Frontier

while hunting i put trk in low four wheel drive and first gear and punch it through the mud hole. After returning and having to drive through it again once i got on the black top road i notice a pining when i push on the gas peddle. I notice no leaking of any fluids or dinted oil pan ither.

Can you help me???

Thank you!!!!!

Asked by for the 2006 Nissan Frontier