Been chasing down a running rich issue for a while now and I made a scary breakthrough tonight. All four O2 sensors are randomly and simultaneously flatlining. When it’s running normal, upstream sensors will oscillate between 0.1 and 0.7 ish volts and the downstream sensors will hold relatively steady around 0.7 ish. Out of the blue all four will drop to 0.000 to 0.030 ish and the car will run like crap, backfire, read -35% fuel trim, etc.
This really worries me. I can imagine one of them konking out, but all four at the same time? This smells electrical to me and I don’t even know where to start.
This really worries me. I can imagine one of them konking out, but all four at the same time? This smells electrical to me and I don’t even know where to start.
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