I Recently had a major failure of a trans cooler line which in addition to creating a lot of smoke against the exhaust also soaked the underside of the engine. I fixed the lines and trans is fine.

a few days later the CEL comes on with code 221. I checked the O2 sensor output to ground and am not getting an voltage cycling, just ~0.6V steady. Creating a vacuum leak or sucking propane into the intake can not change the 02 reading.

Is it reasonable that a 10-15 minute spray of hot ATF could have disabled the 02 sensor? I Seem to recall that is needs an outside aire reference to function.

There is a distinct change in exhaust odor with this CEL code. I;ve also checked the Fuel regulator and check fot leaks.

Thanks,
Matt