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Q: Changed battery, now the engine "chugs" at idle and while accelerating

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I changed out my dying car battery with a new one (of the type recommended for my car). The engine now "chugs" at idle and when accelerating and the "service engine soon" light comes on. Is this a computer problem? fuse problem?... nothing was wrong until I changed the battery.

My car has 140000 miles.
My car has an automatic transmission.

If you disconnected or connected the battery with the key on or any accessory activated then you may have damaged the computer of the car.

Firstly, have the Check Engine Light scanned to see what code is stored in memory. Then open the hood, turn the key off, remove the key, and then close and lock all of the doors. Afterwards, disconnect the battery ground cable and let sit for 10 minutes. Next, reconnect the ground cable and tighten the clamp. Open the door and restart the vehicle and let it idle for at least 3 minutes.

Put it in drive with A/C off and wait 3 minutes. Turn on A/C with vehicle in drive and wait 3 minutes. Road test normally to see if no lights come on and vehicle drives normal. If not then have a mechanic check it out for you to see if the ECM was damaged.

If you need help with this procedure, consider YourMechanic, as one of our mobile technicians can perform these checks and properly diagnose the Check Engine Light firsthand for an accurate repair.

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