[dgelfuso]

Hit a speed bump in a parking lot last week and "engine" light came on immediately on my 2003 Dodge Ram 1500 4.7L. Code is P0038 which is " O2 SENSOR 1/2 HEATER CIRCUIT HIGH".

I quickly looked under the truck but couldn't see a post catalytic sensor. Two questions:
1. Where is the sensor located?
2. What is the best way to fix the problem?

 

[snrusnak]

Could you take a picture of the catalytic converter(s)? I assume it's a somewhat different exhaust setup than on my 2010. My 2010 has one cat after each manifold and there is an O2 sensor in each one.

This is from another forum:
"Your heated O2 sensor has a heeater problem most likely. Most likely time to change out your HO2 sensor. Most cars actually have only primary heated. Not sure for this application but would thus assume the primary sensor or otherwise known as precat O2.

With a sensor high you have high voltage back to the pcm thus most likely shorted heating element.

There is an outside chance of a cross short to the ground circuit of your O2 sensor. If after replacing your sensor you still have a problem then start looking for this.

Just go to you auto parts store and get an HO2 sensor (Should be a 22mm or 7/8" -- same size) and replace the Primary first and then if that does not solve it then see if you have a heated postcat HO2 if not then see above."