Random Misfires?

2001 HYUNDAI SANTA FE
330,000 MILES • 2.7L • V6 • 2WD
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CA7922303
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  • 165 POSTS
Recently I had a no start situation. Installed new CKP sensor. Ran fine for a week. Installed new battery, now misfiring. Code reader shows misfire on #5, old codes misfire on #6 and random misfires. Installed new coil pack. Is running some better but still idles rough and missing on any acceleration. I suspect a bad CKP maybe from O'Reilly's. ECU, PCM were replaced recently.
Dec 22, 2022 at 8:32 AM
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AL514
  • Experienced Mechanic
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Hello, when it comes to replacing sensors and critical components such as ignition coils, solenoids and actuators always try to get the OEM part, they cost more in most cases, but in the long run you will save yourself a lot of headaches. The engine computer uses the crankshaft position sensor to determine cylinder misfires by watching for any cylinders that cause the crankshaft to slow down. And O'Reilly's has had some of the worst parts these past few years. You should do the spark plugs too if you're replacing any ignition coils. Since it's an aftermarket crank sensor, the ECM may also not even be detecting the correct cylinder that is misfiring. Just beware of aftermarket components, you don't want to damage the new ECM.
Some crankshaft sensors also need a crank relearn procedure done when the sensor is replaced. This is done with a capable scan tool in most cases.

There are actually 6 Technical Service Bulletins (2 being Recalls) for the Crankshaft Position sensor. There are 4 of them below, the 3rd diagram has the updated part number from the dealership, It states that the gap for the sensors that were installed stock are not correct, that's why you're having so many issues here.

https://www.2carpros.com/articles/crankshaft-angle-sensor-replacement
Dec 22, 2022 at 9:21 AM
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CA7922303
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4-1-2-5-6-3 is how the Duralast coil is marked. My firing order is 1-4-5-2-6-3. Swapped plug wires and problem solved. I've had this issue before with the same vehicle before but had forgotten. Thanks for your help.
Dec 27, 2022 at 3:25 AM
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