My code reader says P0031 and my CEL, VSC and TC lights are on. I have reset it several times and checked the gas cap. I would assume the P0031 to be the Bank 1 (in front of CAT) sensor. I just replaced this about a year ago. So, do I just replaced both front ones at the same time or just pick one and see if it clears the codes? From the search function on here it seems people often replaced both. Any other things to check other than the 02 with a P0031 code? We are leaving on a trip in a couple of days and I don't think I have time to get a Toyota factory replacement in time. Will a Bosch from the auto parts be fine if I can't get a factory part in time? I'm going to do the change out myself since it's normally pretty easy with the 02 sensor removal tool. It will be going on a 2004 GX470. Thanks!
P0031 and 02 sensor
- Thread starter NCLX450
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
Get Denso. Bosch has a different gradient and will eventually show errors even though it is fine. B1S1 is driver precat so not your cat. If you have all original O2 sensors you can replace as many as you can afford. If you do it. Disconnect your battery while you replace them and it will remap and you will get a surprise in fuel economy and power. Remember to reset your windows and sunroof if you do this.
Did you follow a diy video? My new to me '06 is throwing a CEL with P0031. I'm brand new to this platform!
Upstream O2s are easy to get to and replace (although, make sure the engine is warm but not hot - such as run it for 1-2 minutes before removing the old sensor).
I'd order new Denso OEM-style replacements (Rock Auto usually has them the cheapest). Be sure to use dielectric grease on the connector when re-connecting them. O2 sensors are wear items, by 150,000 miles they do not work as well as they did when they were new. Usually that code is indicative of the sensor itself being damaged.