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Q: Car dying at low speeds. Also hard idle sometimes. Why?

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I have a code that pops up. P0108. The car dies when I am driving at low speeds. I have to put it in park to start it back up. Always does start right back up. Cleaned throttle body so it's not that. Any guesses or recommendations?

My car has 165000 miles.
My car has an automatic transmission.

Initially I would check for broken vacuum hoses or leaks around the intake manifold. Seeing as the P0108 is for a circuit malfunction, the problem is more likely related to an electrical problem. The MAP (Manifold Absolute Pressure) sensor could be malfunctioning, the wiring/connector may be damaged, or the engine computer could be bad.

Once you can verify there are no broken vacuum lines or hissing noises from a vacuum leak, then I would most likely suspect a malfunction MAP sensor or wiring damage going to the MAP sensor. The voltage value of the center wire coming from the MAP sensor should change with the engine off, engine idling, and while revving the engine. If the value does not change, then I would try changing the MAP sensor and then clearing the codes. If you need help having this problem scoped out, a certified professional from YourMechanic can come to your car’s location to diagnose the stalling issue and hard idling problem.

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