I have a 2000 Yamaha ox66 VX225 I Purchesed this Triton boat last year and got no Maintenance Info the motor. It runs a little ruff at low RPMS and smokes a little more at then my old 87 yamaha 150 ..I replaced the 3 low pressure pumps, Plugs and cleaned the O2 sensor fuel filters ect. it seemed to help.. My Questionis is should I replace the O2 sensor as preventive mintenance just because the motor is 10 years old I belive in keeping Maintenance up