Hey guys,

Long time no see. On Monday I was coming home from Volleyball,and it was pouring out. While driving I had the CEL come on,and when I got home I checked the code by going on,and off with the key three times,and I found code P0138. I looked it up,and it said it was:
Oxygen Sensor Circuit High Voltage (Bank 1 Sensor 2)

I did some research,and someone told me it could be that the rain cooled the main catalytic converter so much that the O2 sensor got a bit messed up. I have no idea if this is right,and that is why I am here. Is there an easy way to reset the CEL,and see if it comes back in? Will taking the negative battery cable off fix this temporarily until if or when the CEL comes back on?

Oh yeah this is on an 01 2500 Ram Wagon with 5.2 litre V8,and auto transmission if that matters.


Chris

 

With an O2 sensor the CEL stays on only temporarily. If it's staying on constantly then it's more likely that cold rain water splashing up onto the O2 sensor caused it to crack. If that is what happened, your only option is to replace the O2 sensor. This very thing happened on my Mustang. Drove it through a deep puddle in the rain and ended up having to replace two O2 sensors the next day.

 

How do I know which O2 sensor to replace? It say the #1 bank rear sensor,so is this the one before the cat,or after? I would assume before as it is saying a specific bank,and I assume there is only one after the cat,correct?

Can I remove the battery cable for a bit to see if that fixes it,or are you sure that I have an issue with the light staying on constant the rest of the trip home?

 

Sensor 1 (upstream) is before the cat and sensor 2 (downstream) is after the cat. Since you only have 1 bank, you'll need to replace the one after the cat. As far as disconnecting the battery, you can try it and see what happens, you won't hurt anything.

 

Strange thing happened today. Last night while driving the van the CEL was on the whole trip to,and from. This morning while heading to the dump the light was off,and I didn't do a thing to the van. I love it when they fix themselves.

Chris

78 Mazda RX-7 GS
74 Mazda REPU
74 Mazda RX-4 Hardtop
01 Ram Wagon 2500