Hi Guys,

I was getting the following codes:

P0031 HO2S Heater Control Circuit Low (Bank 1, Sensor 1)
P0051 HO2S Heater Control Circuit Low (Bank 2, Sensor 1)
P0037 HO2S - 12 (Bank 1 Sensor 2) Heater Circuit Low Input
P0057 HO2S Heater Control Circuit Low (Bank 2, Sensor 2)

I checked the fusebox in the engine compartment (Located in the E-Box). Note: There are five 30 amp fuses. The middle fuse (i.e. #3) was blown. Since this is the fuse for the O2 sensors, I realized this is most likely causing the above codes.

I put a new fuse in, and when I started the truck, the idle began violently surging, up, down, up down, up down, etc.. and I saw black smoke coming out of the engine bay. I shut it down to see where the smoke was coming from and it was from behind the engine. It smelled more like burning plastic than anything else. I was slightly freaked out. I tried starting it again and the same thing (only for about 5 seconds before I shut it down). I then removed fuse #3 and restarted the truck and it started right up and the idle was perfectly normal. I put fuse #3 back in, tried it again and more surging and then it started running normally. I was thinking maybe there was a build up of oil/fuel in the PCV system in the back and it just had to burn off. But sure enough when I checked fuse #3 it had blown again, so thats the only reason it started running normally again.

I am wondering if it could be the heating element for one of the O2 sensors getting stuck on or maybe the O2 sensors are shot?

Has anybody experienced this before?

I imagine you have a short in the heater elements, with all those codes it will be in the wiring loom before it splits to the individual sensors, the smell and smoke is the fried loom before it blew the fuse again... Get an auto electrician to look at it...  Pete
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2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

I was hoping to hear I just needed new O2 sensors