My check engine soon light came on again today after about 500 miles since i had reset it last. It's the same code as before, 05 03, the Front Right Heated O2 sensor according to the site. I was hoping maybe that switching up to 91 octane from 87 would fix it but i guess not. I talked to my mechanic a week or so ago when it first came on and he said that it is possible that the sensor is bad since they have had multiple recalls on the O2 sensors with our cars. But he was wondering how i got the ecu code. He had never heard of the way i got the code and decoded it. He says he uses a machine to plug into the ecu and then get the code. I then told him the code i got was 05 03 and he couldn't find a single match in his book. Any ideas?

 

The OBD-II code scanners use different codes than our flashing light system. The ECU code DTC 0503 is P0130 in his scanner. A Haynes manual lists all the OBD-II trouble codes in Chapter 6 Emissions and engine control systems.
-hype