Skip the auto shop - Our mechanics make house calls

Q: Getting code P0303

asked by on

I am getting a code P0303, which is for a cylinder 3 misfire. I am not sure, but I may need a coil replaced.

If you have already taken the first step of getting your codes scanned, the next thing to do would be to have an ignition test performed by a qualified technician. Attempting to do this yourself could result in being shocked by high voltage. This test would entail removing the ignition coil and placing the ignition tester in the circuit between the coil and the spark plug. If the spark plug or coil is faulty, the light will not flash consistently or at all on the ignition tester leading the technician to believe that either the coil or the plug is faulty for cylinder three. After confirming the lack of spark to cylinder three, the technician may erase your fault codes and switch your number three coil to the cylinder adjacent to it. When your Check Engine Light comes back on, if the misfire has switched to the other cylinder, the coil is faulty. If the misfire stays on cylinder three, the spark plug is faulty. If the spark plug is faulty, it is a good idea to have all spark plugs replaced at once.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: My car won't start after replacing flex pipe and Muffler

Technically, there is no connection at all between what was done on the exhaust system and the subsequent no start problem. Of course, it's always possible the Mechanic damaged something on the vehicle but such, if it occurred and if...

Q: Window not working

Hello. I will assume your drivers front window is not working. A mechanic can check the fuses for the window for any that may have blown. In the event of a blown fuses, some trouble in the circuit caused the...

Q: p0303, p1313, p0420. codes come up. no flashing and now signs. what do I do?

Hi there. Sounds like there are a few things going on. First the code P1313 means that the timing chain has jumped a tooth making the camshaft and crankshaft out of sync. The chain tensioner may need replaced if it...

Related articles

P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.