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?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Bank 1 and Bank 2 running lean

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: Vehicle won't go over 20 MPH

With the speed limitation and the loud noise, I recommend not driving the vehicle until it has been diagnosed and repaired. It sounds like the vehicle is either in limp mode or a mechanical failure has stopped the vehicle from...

Q: Is there a constant 12-volt source from the fuse board under the glove compartment?

It does not appear that there is a fuse for the horn located in the interior fuse panel. I would probe the ignition and accessory power fuses to see if they are a constant 12-volt source. If one of them...

Q: Not able to start - 2006 VW Mark 5

Hi there: The P1095 ODB-II trouble code indicates that the O2 sensor signal circuit is slow switching from lean to rich (Bank 1 Sensor 1). When this occurs, it can cause your vehicle to stall rather quickly. However, before you...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
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...
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...