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vipertech763, automotive technician
Category: Dodge
Satisfied Customers: 1854
Experience:  gold certified, dodge viper certified
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Pickup: Dodge Ram..5.7 liter..hemi..the diagnostic code is po138, I

Resolved Question:

Hello, I have a 03 Dodge Ram pickup with a 5.7 liter hemi engine. My engine light is on and the diagnostic code is po138, I could not clear the error , what is causing this?
Submitted: 8 years ago.
Category: Dodge
Expert:  vipertech763 replied 8 years ago.

Good evening, the most likely causes for this code are damaged wiring going to the o2 sensor. The other possible cause is the powertrain controller. This last possible cause is the least likely. Inorder to accurately check the code further if no obvious wiring problems is to you a scanner that can read the o2 sensor voltage.


Here is the actual trouble shooting steps for the code:




If this answers your question then press ACCEPT. If you need more help then let me know. Thanks

Customer: replied 8 years ago.

I just installed a True flow cold air intake system and right after that is when the light came on, the 02 sensor goes into that tube ,I think that it maybe it's not in the right position. what do you think?

Expert:  vipertech763 replied 8 years ago.
The o2 sensor goes into the exhaust.......not air intake system. As long as your sure the code is p0138. You need to look at the exhaust just below both catalytic converterss.
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