Hey guys,

First time joining and posting on a blog, thanks for listening. I have a 2006 Honda Accord (4cyl). No issues at all when I am driving it, but for the past 2-3 months the engine light has been coming on and going off. Most recently it has been on more than off, and has been on for about 2 weeks straight now. I took it by O'Reilly to plug it in and check it and got back 3 codes:

p0420 - Catalyst Efficiency Below Threshold (bank 1)
p0134 - Air Fuel Sensor (Bank 1 Sensor 1) Heater System Malfunction
p1157 - Air Fuel Sensor (Bank 1 Sensor 1) AFS Line High Voltage

Like I said, there are no problems with the car, it runs great and drives great and everything works. Car has about 120,000 miles on it. I have done some research online and it sounds like it could be anything from just an o2 sensor to the catalytic converter. Any information or help that anyone can provide would be very much appreciated.

Thanks

 

Welcome!

The heater (P0134) is normally caused by a failed heating element in the sensor, so check that out. Unplug the sensor & measure continuity across the 2 same-color wires on the sensor. Supposed to be a pretty low resistance (couple ohms?) but they normally fail completely open. If you're lucky you'll show no continuity at all across those 2 wires. You're doing that to decide between a bad sensor vs. bad wiring in the car.

If the heater has gone bad, you have to replace the sensor anyway. So do that first & see if the other 2 codes go away.

 

Note, Air/Fuel Sensor is not an O2 sensor and is a good bit more expensive.

good luck