Bank 1 and Bank 2- Meaning and Location

What is Bank 1 and Bank 2?

Bank 1 and bank 2 simply refer to either side of the engine. Check your owner’s manual or a service manual for a positive location of bank 1 and bank 2. Most commonly, bank 1 houses the front most cylinder on the engine cylinder 1, and bank 2 is the opposite side of the engine. Check out the pics below to see several different configurations.

Tech Tip: The front of the engine is not the part closest to the front of the car. It is the side with the crankshaft pulley (also called the harmonic balancer). No matter the configuration of the car, whether rear-wheel drive or front-wheel drive or the position of the engine.

In each of these banks, you can usually find respective O2 sensors. With the exception of some Subarus, 4 cylinder engines only have one bank. You will often see codes that reference bank 1, and there is only one bank to pick from, therefore, bank 1.

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  1. This helps to clarify the meaning of bank one and bank two

    1. On my 2010 impala I’m getting code p0010 ,intake camshaft position actuator circuit open Bank 1 and p0011 camshaft position timing over advanced bank 1

  2. That’s helpful. Thanks for your post.

    1. You’re welcome, Mohammad. Thank you for kind words.

  3. How about bank 1 and bank 2 for a single exhaust 4 cylinder engine? Is that the front the the rear O2 sensor?

    1. My truck has only one exhaust pipe. So do i have 2o2 sensors or do i have 4 o2 sensors

  4. I renewed this cause car not wanting to turnover some time’s. Won’t even crank,, lights on but have to keep messing with the key trying g to start the car over and over. When it does this , no sound at all, after trying awhile it will start. Than sometimes it just starts right up first time.

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