Whether it's just from a routine scan or a result of a check engine light, discovering a P0171 could lead to various problems that have varying costs.

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The Engine Control Module, or ECM, directly controls the engine. Still, it can’t do that properly without the Transmission Control Module or TCM and PCM, which work together and exchange information.

There are two key numbers you'll find on your car -- the VIN and the Engine number -- and both play key roles in your car's past and future.

What Does Code P0442 Mean? Engine code P0442 means a small leakage in the evaporative emission control system. It is not a critical problem, but it could be annoying and cause something more serious.