Q: Getting code P0303

asked by on March 17, 2016

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

Check Engine Light is on Inspection $79.99 - $89.99 Get a Quote
Spark Plugs Replacement $96.63 - $636.71 Get a Quote

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.

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

What others are asking

Car shuts off while driving. Got fuel pump changed. Throttle position sensor oil pressure switch wires for a tune up done also

Hi there. Usually when a car will stall all of the sudden without warning, it's caused by a restriction of fuel or an electrical glitch with the ignition system. If you've had the throttle position sensor changed, and fuel pump,...

Have a 2002 Chrysler Sebring convertible with airbag light on and horn doesn't work. If the problem is in the steering what would

Hi there. Some airbag light issues are related to wiring problems under seats that are constantly moving. This is more of an issue with side impact airbags than any other type of airbag but it would still trigger the error...

Clutch pedal gets stuck

There may be a problem with the clutch pressure plate, the hydraulic clutch master, or slave cylinder binding. The clutch is the most likely problem, and would need to be inspected to be sure. I recommend that you have a...

I replaced the output shaft sensor. Do I need to reset the code?

Try removing the battery cables and letting the computer sit for about 1 minute and then hook up the cables or if you have a scanner that can erase the codes. This will clear the engine light and codes to...

Check engine sign on

Most Check Engine Lights are illuminated when an error code is triggered and stored in the ECM. Even if you've repaired what was broken or damaged, you still need to clear those codes in order for the light to go...

Car shaking and stalling while driving.

Hello, the place to start would be to have your check engine light diagnosed. I would recommend getting the aid of a mechanic to come out and connect a scanner to your vehicle and see what codes are present and...

engine speed not more than 3500 rpm

Usually when the engine experiences this condition, the issue is related to the [camshaft]https://www.yourmechanic.com/services/camshaft-position-sensor-replacement) or crankshaft position sensor. These sensors monitor the position of the crankshaft and camshaft in order to determine correct fuel and air ratios. If one of...

How much does it cost to replace the lug nut stud on a 2006 Honda Pilot EXL

The cost depends on whether it is in the rear or the front and also on whether there is space behind the wheel hub to push out the stud and draw in a new one. If the wheel hub does...

The trigger wire for ignition coil three has no signal.

The coil in your application has a power wire (red), a ground wire (black), and a PCM pulse command wire (5 volt pulse; Blue w/Red stripe for cylinder No. 3) that operates the coil’s internal switching transistor. Using an oscilloscope,...

Related articles

How Are High-Performance Ignition Systems Different from Standard Ones?
Once Once upon a time, there was only one type of ignition system. It used a distributor, points, a coil, and was subject to significant wear and tear. Then came the electronic ignition, which replaced the points with an electronic...
How to Replace an Ignition Coil
Your spark plugs work with the ignition coil to receive signals from your vehicle’s computer. A bad coil can cause driveability issues like stalling.
How Are High-Performance Ignition Systems Different from Standard Ones?
Once Once upon a time, there was only one type of ignition system. It used a distributor, points, a coil, and was subject to significant wear and tear. Then came the electronic ignition, which replaced the points with an electronic...