I finally bought a scanner to see why my Check Engine light kept coming on('97 4.6 31k miles). I got a code 141 which is an "O2 sensor heater circuit malfunction (Bank 1 Sensor 2)" Does anyone know what this is? My dad said that on his Blazer there is a heated O2 sensor and it is powered by 12v and if mine is the same way maybe I have a blown fuse...If that were the case wouldn't I get it more than once every couple hundred miles? I don't even know where to start, I guess I should probably buy a service manual so I can see where all the sensors and fuses are at....I accidentally found a little black box with small fuses in it on the drivers side fender near the firewall so I'm not even sure what fuses to check! Thanks for any help you can offer

 

Jeremy,

The problem could be:HO2S HEATER CIRCUIT IS OPEN, SHORTED TO GROUND, SHORTED TO VPWR OR EXCESSIVE CURRENT DRAW, LOW CURRENT DRAW. Visually inspect the HO2S circuit for exposed wiring, water contamination, corrosion and proper assembly. Odds are the sensor is kaput. If the connectors are Ok let me know I can give you the whole diagnostic procedure.

regards

Jean Marc Chartier

 

Thanks....I just got this truck so I don't know much about it yet except what I have learned from the massive knowledge of posters here. Do you know which one it is or where it is located? There are several O2 sensors right?

 

That sensor is going to be the passenger side, after the catalitic converter (toward back of truck). I have had to replace that sensor twice. within 60000 miles. Like JMC said, check the wiring and if everything looks ok just replace the sensor. Cost was about $50 at AutoZone. Not sure why mine has gone bad twice but I replace it and after a couple trips around town the check engine light should go out. No big deal.
By the why, how much did you pay for that scanner?

Scott

 

that is a nice looking truck Squanto! Thanks for the info. I cleared the code yesterday and the light came back on this morning...last time it took a couple days. Is the sensor hard to change? I bought the scanner at Advance Auto for $149. It is pretty nice compared to the old ones like my ranger had...where I had to plug it in under the hood and count beeps! Thanks again

 

Sounds like you must have got the Actron OBD II scanner if you bought it at Advance Auto. It's not a bad scanner, I have one myself and find it very easy to use. If you ever happen to need an update just call Actron and they can help you out. At least that is what a tech at Actron told me, when I called for a customer that wanted the latest possible update in their scanner.