You will not be disappointed in the Diesel oring kit. I have done at least 10 using his kits. It is not hard, just take your time. I tied a 10' piece of wire to the brush in case I dropped it. Never did. I have tried the RTV. It simply doesn't work.
The one thing I did notice with new FRP is KOEO voltage. The old sensor read .37 volts new sensor KOEO .50 volts. That is what leads me to believe it was the sensor all along.