Code PO303 Cylinder #3 not firing properly. Had replaced ignition. Coil and Plug on 10/06/2014 $565
Now 2017 can feel the hesitate. Engine light on. But when car warms up Car runs okay. Could it be the coil/spark plug again? Same Cylinder. Wonder why is disappears. Cars years ago the plug stay bad until you replaced it period

Assume nothing.. have car scanned for codes again. Might be a different cylinder or something completely different.

Thanks

Luckily most auto-parts store will do a free scan for you these days. So you can make your decisions without the time and cost of a dealership diagnostic service. If you have an Android phone you can get an app for free what will work, and all you need is a Bluetooth adapter that plugs into your ADB port you can get for less than $20. If you do your own work..and have a vehicle newer than 1996 that's a worthy thing to have. I have that and a D-CAN usb cable for my BMW and other vehicles. Saves even a trip to the parts store. Or if the car isn't drive-able.

Yes I have a code reader. Operates with the Android phone.

Useful Item, isn't it. Even if you may not need it very often.

Each component can be tested to verify the actual failure. The hard part is now finding that one shop that can diagnose the fault and make only the needed repair.
With the stumble clears after it been running a while, you may have a leaking injector that is fouling the plug until it's warmed enough. Or it could be coolant fouling the plug and slowly burning off. Again, testing needs done first.

I used for the first time your mechanic . It was great. They come to your house.He found the coil was going bad in cylinder 3, like the code reader said. He also did all the other cylinders coils and plugs and ignition wires. Just for $180.00
Pepboy charged me $560.00 just to do one coil and plug in 2014 cylinder 3.