I have a 2005 Dakota that I recently purchased knowing it had a few issues. It has the following codes p0499, p0031, p0037, p0051, p0057 and also has the air bag light on. The guy I bought it from told me the oxygens sensors were out and the airbag light was due to the recall. SO obviously 4 of the 5 codes are O2 sensor related, all having to do with the heater circuit. So my question is is it more likely that all 4 heaters are out as well as the purge valve, or is it more likely the PCM is hosed? Is there a quick check that can be done to verify the O2 heater is actually out? How about the purge solenoid? I went to autozone and dropped $25 for a Haynes manual to have it tell me "diagnosis of the NVLD system is beyond the scope of the home mechanic. ...have a dealer service the vehicle" so any help on testing either of these before changing them is appreciated. I'm assuming the O2 sensors should have a resistance range for the heaters to fall in as well as the solenoid. And lastly is it possible to get a used PCM and have someone flash if for the vehicle?