My car's check engine light has been coming on. It has given me this code twice: P0171 (Bank 1 too lean). The first time it happened, I had the light turned off to see if it would come back. The first time it the light came on, I chalked it up to being the cold and dense air outside and the vehicle not being able to catch up. So, the light stayed off for about a month. Then, it came back on after another really cold day, and it gave the same code. My car is idling a bit lower than usual, and has for awhile even before the check engine light came on. I've noticed no major difference in performance or power in my car. Autozone gave me a print out of possible solutions to the problem, the easiest being replacing the O2 sensor on the manifold. Any advice or other ideas?
Cold weather causes plastic and rubber components to contract. The intake manifold on my truck would expand and contract every winter, setting P0171 and P0174 lean codes. Then finally, this past winter, the manifold cracked. My guess is that you have a vacuum leak somewhere due to shrinkage from the cold weather. The source of the leak could be anything from a vacuum hose to an intake manifold, like my truck. A trained professional will be able to pinpoint the leak using a smoke machine. I suggest you contact a trained professional to diagnose your Check Engine Light code firsthand, they will be able to follow through with the necessary repair procedures in order to fix your vehicle.
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