Oh I didn't know there was OBDIII cool

 

These go to eleven

 

I found out my code. It is P0138.

Thanks in advance for the help.

 

There isn't. OBD-II is '96-present, all makes and models,Import and domestic.

P0138 Is bank one (driver side) downstream O2 sensor. Depending on the year of your ram and cali vs. federal emissions, it may only have one downstream sensor. This code indicates that the signal has shorted to voltage. Most often, the heater and signal circuits cross internally and you just replace the sensor. But check the wires first.

 

Thanks I will check into that.

 

I have a new twist. My check engine light went out on it's own, but I have been getting bad gas mileage so I know there is an issue. I don't want to replace the O2 sensor if it's not bad, but I don't want bad gas mileage either. Any ideas?

 

The O2 sensor (both upstream and downstream) should be replaced ~ every 60K miles. Failing to do so can result in the cat clogging. $120 for two O2 sensors is cheaper than $120 for 2 O2 sensors + $200 (minimum) for a new cat.

 

Changed the O2 sensor that was correlated by the error code, reset the truck computer and drove for a tank of fuel or so. No increase in MPG's and then the light came back on. Obviously it was not the O2 sensor. I need to try something else. Any ideas?