aso432 New member Aug 12, 2018 #1 I pulled code 21 by jumper mode. It looks as though it is an O2 issue. How do I know which Sensor needs to be replaced? Thank you for your assistance.
I pulled code 21 by jumper mode. It looks as though it is an O2 issue. How do I know which Sensor needs to be replaced? Thank you for your assistance.
