I have a 96 Taurus 3. 0 DOHC motor. It has 116,000 miles on it and the inspection is due in July and I would like to get this problem solved. I have a code 0420. Catalytic low efficiency bank 1. What is the best way to go about fixing this problem. What are the normal voltages for the o2 sensors. Also there is a exhaust leak in the flex pipe. This is after the converters. Would this make a problem like this. I can get all the monitors to go into ready mode except the cat one with the check engine light out. According to NY inspection law on a car older than a 2000 you are allowed 3 monitors to not be ready and pass. Will I pass with this monitor not ready. I also need to replace the intake manifold runner control. Would this affect the car.