Hey guys my 05 Nissan navara d22 3L has developed a really bad surge it's that bad it spilt half my coffee all over my lap I have replaced my fuel filters and blew the fuel lines backward my mechanic has quated $5000 for the injectors to be checked btw the motor has done 300,000 so is it worth to check the injectors or just get a second hand motor please help me out guys cheers