My advice to this, is to use an actual thread sealant not teflon tape, and if possble, use a steel adaptor or t-fitting. I used a brass fitting for my first OP install years ago, and teflon tape, and the sender was not grounding right. It was sending incorrect numbers making me think OP was low. I changed to a steel T fitting, and used a thread locker/sealant. Have not had any issues sense then.