I have all four of the above codes that eventually cause a check engine light. Last time I cleared it it stayed off for about 2-3 weeks before it came back. It seems like all 4 sensors are involved here and the shorted/open codes contradict? So maybe not the sensors and there's another issue with the ECM? If the sensors weren't so damn expensive I'd change them all but I'd be more than a little annoyed if that didn't clear the codes. The car is running pretty well as is, but that check engine light is mocking me. Any thoughts?

 

Oxygen sensors are wear and tear items. They do not last for ever. Can you tell me the last time you have replaced these sensors?

 

I just purchased the car a couple of months ago. I'm going to assume they have not been replaced. It only has 97,000 miles on it.
I'm just a little confused by the nomenclature of the codes, i.e. all 4 sensors open and shorted? I'd hate to replace them and find out it's something else. I think I'll unplug the connectors and spray them with contact cleaner first.

 

It is peculiar that all four went.

All oxygen sensors are tied back to an EMS Power Relay. That is the only circuit all four would have in common.

Other than that, you could have corroded EMS terminals. That is free and easy to check.

97,000 miles for oxygen sensors is certainly past their prime. They are due for a change.