Skip the auto shop - Our mechanics make house calls

Q: Bank 1 and Bank 2 running lean

asked by on

I've done the tuneup on my car. I had the rear spark plugs replaced. For that repair, the manifold had to be removed. After this, the error codes popped up. Those are Bank 1 and Bank 2 running lean. What should I do now?

If lean faults occur after the manifold was removed and reinstalled, this indicates a vacuum leak which also means that unmetered air is coming into the intake. Either a vacuum line or induction pipe is loose, or the manifold is not seated correctly. The repair needs to be double checked. If no obvious items are found, a smoke check of the induction may need to be performed to locate the source of the unmetered air leak. You may want to enlist the help of a mechanic, such as one from YourMechanic, who will have the equipment and training to diagnose the error codes and help you move forward with the appropriate repairs.

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: Why does my V8 sound like a V6 some of the time in my 1982 Mercury Grand Marquis

Hello. I would need to hear how the engine sounds in order to be able to know what it may be doing. If the engine is getting hot fast but is not actually overheating then that may simply be a...

Q: Clunking under acceleration

Sounds like you might have a broken motor mount. Broken mounts are a common issue and easily fixable. Most front wheel drive cars have 3 engine mounts and 2 transmission mounts. Some have additional torque mounts, so no need to...

Q: intake manifold question

I do not see the manifold listed that you mention, but the intake manifold to head should have a gasket on both sides for the lower intake and you can use grey RTV around the coolant passages. If you 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...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...