2001 Dodge Dakota Club Cab 4x4 Sport Plus 4.7L - P0155 O2 Sensor Heater Circuit Malfunction Diagnosis
Suddenly, my 2001 Dodge Dakota Club Cab 4x4 Sport Plus with a 4.7L engine begins to sputter, choke, and gag — just days before I need to replace the bed tabs. The check engine light comes on unexpectedly, and unfortunately, I'm currently facing tight budget constraints. I used my old OBD-II scanner and retrieved code P0155: 'O2 Sensor Heater Circuit Malfunction (Bank 2, Sensor 1)'. This is the first oxygen sensor on the passenger side. Earlier, I saw a P0132 code, but it hasn't reappeared. A local mechanic suggested that the P015-5 code might not be caused by the sensor itself, but rather by another underlying issue. He charged $79 for his first hour of diagnosis — which could be applied toward parts and labor if repairs exceed that amount. This is quite expensive for a DIYer. I'm looking for clear, step-by-step guidance on what to check myself before taking it to a shop. Any advice or troubleshooting tips would be greatly appreciated!
The only code present is P0155 — O2 Sensor Heater Circuit Malfunction (Bank 2, Sensor 1), which is the first sensor on the passenger side. Start by checking fuse U (20A) in the Power Distribution Center (PDC). If it's blown, that could be the root cause. Next, inspect Bank 2, Sensor 1 (B2S1): ensure there’s a solid 12V supply on the orange/dark green wire. Note: A P0155 code should not typically result in poor drivability or engine performance. This makes it more likely that the issue is electrical rather than sensor-related. Begin with these checks before moving to further diagnostics. Do you have access to an OBD-II scanner? For reference, see: http://www.obd-codes.com/p0155