Q: Bank 1 and Bank 2 running lean

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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.

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