So I've had this issue since I bought the car a year ago. I get o2 sensor CEL that's always been on and off. When it first started it would come on and then go away for a couple months. Now it's on and off every cycle. Last summer the resonator disintegrated and clogged the exhaust causing it to choke the exhaust. After we gutted that and replaced the resonator the code started to come and go more often. The o2 sensors are already Spaced and double Spaced. I'm trying to figure out what's my best way to get rid of the code for good. But I always hear about spacing the sensors is a way to dummy the sensor. So why would it still throw a code. Could the o2 sensors actually be bad? Or would a simulator be a sure fix. My inspection is due again at the end of this month so I'd like to get this figured out and be done for good with it. YES I KNOW THIS IS ILLEGAL PLEASE SAVE THE LECTURES. Thanks

 

SINCE YOU HAD A CLOGGED RESONATOR, WHAT MAKES YOU THINK ALL OTHER CATS ARE GOOD

DO THIS, ADD LACQUER THINNER TO YOUR GAS TANK (NOT PAINT THINNER):

VIDEO

https://youtu.be/5icTmYItwiE

 

The cats are gutted that's why I get the 02 code

 

Gutting a resonator isn't illegal, sounds like you actually gutted a catalytic converter further down the line (that's illegal)!
is it a 4 cylinder or 6 cyl?
READ: AGCO Automotive Repair Service - Baton Rouge, LA - Detailed Auto Topics - Catalytic Converter Problems
Change your PCV valve, Mazda dealer NEVER EVER DID.
A faulty PCV could send unwanted oil to your catalytics!
Are you using oil?

Just read your last post, and yes that is why you are getting cel code. can't help you, good luck

 

I didn't gut the cats they were gutted years ago I'm sure but we just gutted the resonator bc when it disintegrated it clogged up and choked the exhaust. It's the 3.0l v6