Skip the auto shop - Our mechanics make house calls

Q: Bank 1 too lean

asked by on

Check engine light is on got it tested and it said Bank 1 too lean do I need to change my O2 sensor or egr

My car has 174116 miles.
My car has an automatic transmission.

A: While a bad O2 sensor can be the cause of a...

While a bad O2 sensor can be the cause of a ’lean" fault code, it can be set for a number of reasons. A vacuum leak anywhere in the intake system can cause a lean fault as can other sensors like the mass air flow sensor. Also, any bank 1 cylinder that may be misfiring due to a faulty spark plug, ignition coil, or improperly firing fuel injector can set that fault. A certified technician can diagnose the why the check engine light is on to isolate the exact cause of the lean fault code being set.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: How do I turn the power liftgate feature on or off?

When the power liftgate feature is turned on, the trunk will automatically open fully when the Open Truck button is pressed. This feature can be turned on or off with just a few steps: 1. Press the Up/Down buttons on...

Q: How hard is it to change the O2 sensors?

Hello. I have never seen all four oxygen sensors go bad on a vehicle all at one time. They will fail one at a time and the only time it would need all four would be if they failed one...

Q: truck cranks but wont start

Verify that the fuel pump is getting power when you crank the engine. You should have 12 volts at the connector. If not, then the fuel pump circuit has to be diagnosed. Start with the basics. Make sure fuses are...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...