Thursday, October 11, 2012
Tundra AFR Sensor Code O2, O2
The Front O2 sensor(s) on a later model Toyota Tundra is really called an Air Fuel Ratio sensor. It usually develops a heater circuit failure around 90K miles or later. This ToY fit those parameters & the check engine light was on.
Why did it fail? Read on..
How long does an average incandescent light bulb last? If you stuffed it into your exhaust subjecting it to extreme heat and vibration it wouldn't last 10 minutes.
Now take a heat emitting element & enclose it in metal. In this scenario you’re the computer and you Command it to get real hot, real fast. How long will it last? Environment determines life span and this is a harsh environment. Temps range between 600 to 900 degrees Fahrenheit, not including that it’s getting splashed with water. A good reason light bulb elements aren't used and you just learned something!
Repair on vehicle!
Since the AFR Sensor failed it needs replacement, but look, there are serious side affects you discover upon removal. All the threads are mushed over or as some would say; stripped.
What to do!? Do you replace the exhaust manifold to get new threads or do you chase those old threads and regain 70% or more.
I did the “chase-the-threads” thing as an experiment and this customer was lucky. Fewer problems seem to defeat the experienced technician, special tools help as well.