[coonbusterjack]

I just took my truck in my dealer... I had new tires, Spark plugs (since it had 99,885 Miles) and oil and filter change. I drive to Tennessee and the check engine light comes on (P0171 and P0174 codes)! It has never came on before! Is this something that happens once it turns 100,000 or is it time to replace the O2 sensors?

 

[WhiteBoyZ71]

https://www.obd-codes.com/p0171

https://www.obd-codes.com/p0174

 

[esox07]

While those codes reference the O2 sensors, it doesn't mean that they are the fault. It could be a number of problems causing those codes. Vacuum leaks, bad MAF, etc... The O2 sensors are simply the sensors that are detecting the problem. Sure the sensors can and do go bad, but automatically blaming them is like blaming a messenger for bad news.

 

[GR2017]

While those codes reference the O2 sensors, it doesn't mean that they are the fault. It could be a number of problems causing those codes. Vacuum leaks, bad MAF, etc... The O2 sensors are simply the sensors that are detecting the problem. Sure the sensors can and do go bad, but automatically blaming them is like blaming a messenger for bad news.

Absolutely. They are the messenger, not the problem.

 

[GR2017]

I just took my truck in my dealer... I had new tires, Spark plugs (since it had 99,885 Miles) and oil and filter change. I drive to Tennessee and the check engine light comes on (P0171 and P0174 codes)! It has never came on before! Is this something that happens once it turns 100,000 or is it time to replace the O2 sensors?

You didn't mention if the vehicle is operating normally or not.

 

[coonbusterjack]

Thanks to all! Truck runs fine other than a little hesitation when you start it. The hesitation was not there before.

 

[CritterGitter]

Where do you usually get gas? Do you normally go to just that station to fuel up? This could be just a finicky problem caused by a bad tank of fuel.... I've seen lots of vehicles have downstream sensor issues that were resolved by getting fuel somewhere else... Worth considering and maybe try cleaning your MAF. Always start with the quick/easy stuff first...