do i need an oxygen sensor?

[eliaslear]

judging from the readings from the passenger oxygen sensor data, would you guys say i need a new oxygen sensor? doesn't seem to be switching like the driver side.

https://drive.google.com/file/d/0B6MODaaUExSmU1Z0T1VMWHFETjQ/view?usp=sharing

 

[adsm08]

Well, you either need an O2 sensor or spark plugs.

How does it run?

 

[eliaslear]

well, i bought the truck recently and it was running and idling like shit. i didn't notice there was no check engine bulb when i bought it as we don't have emissions here and in alabama most vehicles have the light on anyway as people don't really care about their cars here. the last owner for some reason decided to replace bank 2 injectors. i assume he grabbed some flex fuel injectors from the wrong truck on just the easy side which is why only three were replaced without having to pull the intake. i put a bulb in for check engine and ran codes which showed i had a stuck rich condition on bank 2. so after investigating, i ran part numbers and sure enough the injectors were the bigger flex fuel injectors instead of regular gas injectors (i noticed they had an extra 4th hole in the spray atomizer which is what got me to looking up the part numbers). so i replaced them with some gas only injectors and the truck runs perfect now. however, i have no idea how long the truck has been running like that, dumping fuel on that right oxygen sensor. it looks to me as if maybe it's been fouled for a while as it's as black as the old spark plugs on that side (before i replaced them the left bank plugs had a perfect color to them and the right were covered in black shit). i'm also probably going to replace the y pipe as mine has precats and i'm sure that extra gas has ruined the passenger precat. btw since i have your attention, do any of the older 3.0 have a non precat y pipe?

 

[RonD]

O2 sensor regularly lasts 120-150k miles, they start to run engine richer as they get older, not as rich as you are describing but they will cost you money in MPG over time.

So, yes, I would replace O2 sensor(s) from your description or even if over 120k.
Price of new O2s pay for themselves over the next 120k