Byrdman

Had the check engine light appear with a 0420 code & was hoping for an easy fix like gas cap or bad gas but no such luck. After resetting the code, took 220 miles for it to trip again.

Had a friend with a shop take a look at it. Bank 2 sensor 1 was completely dead. He also said that Bank 2 senor 2 looked was within spec but a little slow to react, thought the build up of running with a dead O2 sensor could have played a role in that. Both Bank 1 sensors checked out fine. So he plugs in a new one for the dead one & runs it for a while without any codes. About 8 miles into my commute, trips the check engine again also with the 0420 code. What makes it confusing for me is that i thought that code was Bank 1 related only to have a Bank 2 sensor dead when hooked up to the scope. The converter was replaced under warranty a few years back with 50k+ miles and currently have 113k so hoping it's not that . The car runs great.

Any thoughts on what to do next? Start replacing Bank 1 sensors?

Appreciate any insights,
greg

RTIS250

iTrader: (9)

With that many miles on the car, its usually a good idea to replace both forward sensors at the same time. What happens is that the new sensor is now super responsive and reactive, and the other forward sensor is a little slower due to age. Even though both are working properly, one slower than the other, it can trip a code. Above 100k miles, if i ever see an O2 code, i recommend to the customer to replace both forward sensors.