Misfires, spark plugs and sensors...oh my!

I have a 2008 Chrysler Sebring 2.4 L. Runs sporadically crappy. I got it home after it wasn’t running well and hooked up a reader. It initially pointed to the cam sensor and then also got a code for crankshaft sensor circuit and a code for camshaft relearn or something. I was getting misfires on cylinder one. I changed out the cam and crank shaft sensor’s. No luck. I’m getting misfires on cylinder one and Cylinder four. On Cylinder one, early on, I replaced the spark plug and the boot and spring since I have a coil over plug. I’m wondering if there’s anything else I can check.

What were the codes you pulled?


I don’t remember the cam sensor ones but here are two of them that I’ve gotten. Now all I get is 300 multiple misfire. I have attached the codes I got previous. This was prior to changing the sensors.

The other was p0335, p0458, and p0457

The first thing I would check for is a worn timing chain.



OK. Never done that but I’m a master at finding out how to do things on YouTube

Thanks! I appreciate your help

So after replacing the crankshaft position sensor, you’re now getting P0300 random misfire . . . ?

On many vehicles when you replace the crankshaft position sensor you must perform a relearn procedure

Many times you can get away with skipping this step

Other times, you will have persistent misfire and codes until you perform this step

Another thing to consider . . . you might want to consider performing a compression test on all cylinders to make sure your engine is mechanically healthy. If you do this, please post the numbers

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Given that you’ve already done the most likely replacements, I think your best bet is a proper shop diagnosis at this point. They’ll have the Chrysler scan tool and will be able to verify the crank and cam sensor are working correctly. Replacing the sensor itself might not work if the problem is the wiring harness or the thing it senses, or the distance between them.

If your cars has a separate ignition module, that’s also a possibility. p0300’s can be caused by fuel system and air/fuel ratio problems too, so ask your shop to check the fuel trims.

I kind of doubt it . . . given the fact that Rockauto shows coil on plug ignition for this car

I am going to try the relearn since i changed out the sensors.