Having problems with your 2001 Hyundai Sonata ?
Hyundai sonata 4 cyclinder touble code P0171
\015 Check engine light\015
Sometimes the mass air flow sensor will become clogged with some miniscule particles of dust or whatever else. When you open up your hood somewhere near where the air filter box is, there will be a hose running from that to the engine, the mass air flow sensor should be somewhere in near there. They are easy to remove and should be held in place with a few screws. Make sure not to touch any of the electrical connectors on the inside or allow them to get dirty. I used mass air flow sensor cleaner from the local parts place but it is a bit pricey. There may be some alternative cleaners available that are not as expensive. Take the sensor to a relatively dust free area and spray it all over with the cleaner and allow to dry. At the same time under the hood where the sensor was spray that area as well. Once the sensor has dried out re-install it and you should notice an improvement. If the problem still persists you may need to change your spark plugs, or spark plug wires.
Mass air flow sensor could be the cause. you can try and clean it with some throttle body spray.
Repair Help & Product Troubleshooting for 2001 Hyundai Sonata
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