Code 44 only when it rains

[uncle-vinny]

Any ideas on this one? Van is a 1988 Astro 4.3, auto, 115,000 miles completely stock. It runs perfect. When it rains and if I drive through some really deep puddles I get a check engine light but it still runs fine. After about 20 minutes of driving the light goes out. If I read out the code, it is code 44 which is the oxygen sensor. Since it is in the exhaust pipe close to the road I think it is getting wet. The sensor is about a year old. I disconnected the plug cleaned the contacts then used dielectric grease inside both connector housings and put them back together. I am now waiting for the next time it rains. Did this ever happen to anyone? Thank you.

[kings-x59]

So...how'd it turn out? solve the problem?

[uncle-vinny]

Don't know. It has not rained heavy enough since I worked on it. I'll let you know when it does.

[Smiliesafari]

Are there any shields missing? It could be that a sudden soaking with cold water is causing the O2 sensor to give a bad signal. And then when it warms up it goes back to giving a proper signal. Just a thought.

[uncle-vinny]

Not that I can see. Everything looks to be there. The oxygen sensor is in the exhaust pipe very close to the ground. I was thinking could the water from a puddle get the pipe and sensor so wet that it gets cold? The output from the sensor goes out of spec so you get a check engine light. Then when it warms back up to the temperature it was the signal is back in spec and the computer turns the check engine light off. Just a theory. I'll let you know what happens. Thanks.

[mikedamech]

Hey uncle V, I was wondering if the O2 sensor is getting soaked when you go in puddles. The way the O2 works is @ 600 degrees F the inner workings of the O2 measure the Oxygen content of the Exhaust and through a hole in the housing compares it to the outside air. Being that there is 14.7 % Oxygen in the air we breath that is the baseline for the perfect mixture of fuel to Oxygen in the engine. 12% would be rich, 19% lean. So if the hole is blocked you might be confusing the computer.

[uncle-vinny]

Thanks Mike. I think it might be getting wet. I suppose I can spray water on it from a garden hose and see what happens.