Please help. I'm getting a P0138 code on my truck. Its a 5.7 Hemi 4x4. I read what the code means which is O2 Oxygen Sensor Circuit High Voltage Bank 1, Sensor 2. Problem I'm having is that I only have one exhaust pipe. Can anyone tell me how to solve this riddle. I spoke to the dealer and by pulling my VIN it tells them I should have two exhaust pipes. Your help is always appreciated.

 

Did you buy the truck used? If so, the previous owner may have modded the exhaust. I would see if the sensor exists; I would imagine that both O2 sensors would be installed to the same pipe if there was only one...

 

High Voltage Means you are Running rich (More gas being delivered than suppose to)Your Post Cat o2 senosor is prolly going out, What year is your tuck? If its past a certain year you have 4 o2 sensors instead of 2.
Rockauto.com has them for half the price of parts stores. Make sure if you do buy a new one that the brands match or you will have more problems.

After you replace the sensor your truck will thank you with some better MPGs

 

I did buy the truck used, and the sensors (both) are still their. In regards to the year its an 03 mfr date 5-03.

 

you should have 1 pipe on each side off the exhaust manifolds. sensor 2 is after the cat. bank 1 I believe is the passanger side. Willdikem66 is correct should be 4 o2 sensors total. It is still single exhaust. Also known as 2 into 1.

 

Only 2 o2 sensors on your 03 thank god, 30 bucks for the sensor and you will be back on the road.