Hi guys I have a 2001 Dodge Dakota 4.7 , truck started running poorly and the check engine light came on. codes are P0136,P0051,p0031. thought it might be a sensor shorting or a wire touching. So I disconnected all 4 sensors and it still blows the o2 sensor 20 amp fuse when I turn the key to acc. Checked for frayed wires but didn't see anything touching. I'm stumped any ideas would be greatly appreciated. also removed the o2 sensor relay from the PDC and it still blows the fuse. Could this be my PCM causing this issue? what is that 20 amp fuse protecting the PCM? maybe a wire touching I'm not seeing? I attached a pic of the fuse is blowing

thx in advance greg

 

You have a short in the wiring somewhere if it still blows the fuse with the sensors disconnected.... Might be right under the power box there... but, could be just about anywhere. Check where the harness runs down under the truck. Sometimes they will end up on the exhaust manifold, and all sorts of fun ensues....

 

Had this happen after a transmission swap. The goober who put the transmission in pinched the o2 harness with the top of the trans. Still a bit annoyed with how much time I spent trying to figure out my mistake.

 

Thank you for the info ill check it out, had my transmission worked on last year