Mazda Repair Questions? Ask Mechanics for Answers ASAP
Hello, I hope the following assists you.
The codes P0032 and P0038 refer to both lambda (HEGO, oxygen) sensors, the codes relate to both heater circuits for the sensors so it's unlikely that both sensors have failed and is more likely to be a power or earth failure to the sensors. Check that there is 12 volts to the heater on each sensor and that there is an earth at each sensor, the earth is controlled by the engine management so it's unlikely to be this as each sensor is earthed at different pins on the engine management where as the 12 volt supply is from the same source.
The P0421 catalyst warm up code is probably due to the heater circuit not operating correctly on the sensor after the catalyst so start with checking this sensor heater operation.
Let me know if I can advise further and I'll reply as soon as I'm able to.