Help w/engine code

[bigfeet]

Hello everyone. As I was driving down the hwy thinking how great my Tahoe has been running the engine light came on. The scanner says lean condition bank 2. I cleared code and it has not returned in two days. Any insight would be appreciated, thank you.

 

[WayneS]

I believe that is referring to your O2 sensor in bank 2, which should be the one after the catalytic converter.

 

[gpracer1]

Bank 1 should be the driver side, bank 2 the passenger side. It is most like the pre cat sensor, that actually reports rich / lean to maintain 14.7 to 1.

The actual code would tell you. It will be something like bank 2 sensor 1.

 

[bigfeet]

Yes, and thank you. But does that mean I need a new sensor or is there a lean condition for some reason?

 

[gpracer1]

Yes, and thank you. But does that mean I need a new sensor or is there a lean condition for some reason?

Thats the million dollar question......and why it is important to have a good tech able to diagnose the problem.


It could actually be running lean on that bank, meaning maybe a vac leak, injectors clogged, etc.

Or the O2 sensor could be on its way out or "lazy".

Also check for exhaust leaks from the manifolds to the sensors. If you have any "tick tick" sounds on acceleration, you may be leaking.

I would let the truck warm up all the way, then spray some carb clean around all the intake hoses and manifold area and see if the engine reacts. Then try a bottle of techron in the tank to clean injectors, and last replace both O2 sensors bank 1 and 2 if they have more than 80K miles on them.

 

[bigfeet]

Awsome info, thank you.

 

[bigfeet]

I did the carb cleaner test, negative reaction. I also added the Techron treatment. I was wondering after four days why the CEL has not returned ?

 

[gpracer1]

I did the carb cleaner test, negative reaction. I also added the Techron treatment. I was wondering after four days why the CEL has not returned ?

Depending on what code it is, some only light the CEL when it is active, others keep it on till enough key/driving cycles turn it off, if it doesnt happen again. It should be stored as Hxxxx history.