P0171 System Too Lean Bank 1

[aerial_22]

I have been getting an intermittent check engine light the past few weeks. With this condition I have noticed a drop in fuel mileage, as well as poor idle. I had it checked out and it threw the P0171 code for System Too Lean Bank 1.

I have replaced both the upstream and downstream O2 sensors within the past few years. My engine is at roughly 263,000 miles.

My thoughts are a bad MAP sensor, as I still have the original sensor.

Anyone have experience with this code and had to replace a MAP?

Thanks in advance!

[aerial_22]

Anyone? Could really use some advise on this issue. Thanks!

[bern]

The P0171 DTC is usually set when their is a vacuum leak. You can spray Brake cleaner or carburetor cleaner Around the intake manifold, the brake booster hose, the purge valve hose. test the purge valve by disconnecting the wire connector and the evaporative hose that leads to the back of the car and gas tank. with the wire connector removed the valve will default closed. with the engine idling their should not be any air sucking in the port you removed the evaporative hose from

[aerial_22]

Originally Posted by bern

The P0171 DTC is usually set when their is a vacuum leak. You can spray Brake cleaner or carburetor cleaner Around the intake manifold, the brake booster hose, the purge valve hose. test the purge valve by disconnecting the wire connector and the evaporative hose that leads to the back of the car and gas tank. with the wire connector removed the valve will default closed. with the engine idling their should not be any air sucking in the port you removed the evaporative hose from

Thank you!