In April of this year, my XC90 passed a smog test in California. Then a month later I was rear ended on the freeway. The impact was on the driver side of the bumper right where the tail pipe is located. Fast forward to June, my engine light goes off. The dealership says that both bank 1 & 2 are bad as well as both upper and lower sensors. My question is this: could the accident have caused the catalytic converters to have failed? The auto body place found a dent in the pipe that runs between the muffler and catalytic converters. But it doesn’t look big enough to impair the air flow. Has anyone dealt with a similar situation?
All help is appreciated!

 

not likely all the O2 sensors would fail at the same time so you need to check for wiring issues including ground points for the exhaust, then work backwards with a wiring diagram to look for common circuits/components. You should be able to test the sensor individually as well. Finally do you know what fault codes are being reported? that will give you an idea of what's going on. To note, these cars use heated O2 sensors so each sensor has 4 wires - two for the heater circuit and two for the signal. I'm wondering if the accident moved the exhaust system far enough to damage the wires for the sensors, so I'd check the codes to see if they are reporting open circuit/no signal etc then inspect the wire, test for resistance/voltage.

PS if the cat were damaged, you would fail emissions and assuming the sensors are working, you'd see a P0420 / P0430 code etc .

 

MT617, Thank you for the feedback. I will be sure to bring this up with my mechanic!