Hello all. This is my first time posting on this forum. I have a 2008 Prius that I bought used in spring of 2018. For about 18 months on and off, I have driven the car in attempt for get all of the monitors ready. I have also followed the drive cycle specification. Within the past year, I have driven the car hundreds of miles with the following results repeatedly: - I reset the ECM - I drive hundreds of miles, frequently checking monitor statuses and DTCs - No DTCs ever appear - The only monitor left to complete is the oxygen sensor one - When I reach a certain mileage, the large red triangle appears, along with multiple amber lights, of which I forgot to take note - I reset the ECM again Does anyone know why the oxygen sensor monitor never completes?
Welcome to PriusChat! How many miles are on the vehicle ? How are you monitoring for DTCs (which device, etc) ? When was the last time the oxygen sensor was replaced (upstream or downstream) ?
Well I had another vehicle with the same issue. The monitors were never complete and therefore in Virginia I could not pass emissions to renew my registration. After extensive research and two dealer diagnosis visits it was never resolved. Luckily, I learned about a technicality, the Ford Excursion was over 8500 pounds and was allowed to pass emission with the old tail pipe sniffer. I am glad I do not have to deal with anything similar anymore because both my 2006 Prius are exempt from Emission testing in Virginia.
The vehicle currently has a mileage of 166,520. I use an ELM327 WiFi OBD scanner along with OBD Auto Doctor on my laptop. The downstream O2 sensor was replaced earlier this year, with a Kwiksen brand OEM-compliant sensor. After a few months, the upstream O2 sensor was replaced with a new eBay one, which caused DTC P2237 to appear, so it was again replaced a few days ago with a used (junkyard-sourced) O2 sensor which had no DTCs. However, the upstream usually has a reading between 2 and 6 volts, according to a graph shown by OBD Auto Doctor, regardless of how many times I've replaced it.
Never heard of the application before, my guess is OBD Auto Doctor isn't offering you the DTCs needed. Please find a generally recognized app or program from this forum and try scanning again : Prius OBDII Third-Party Apps | PriusChat
Will try a different OBDII app, but the vehicle finally threw a code, P0A80. I might consider selling it at this point.
