P0303 code
03-03-17, 03:25 PM
#1
Pole Position
Thread Starter
P0303 code
Hi all,
Dad coincidentally drove the car one day and told me the CEL light was on and sometimes blinking. I started the engine today and the light was on with what seemed like a rough idle. Shut off the car and scanned the system pulling up P0303 which apparently is for cylinder 3 misfire.
Car has about 150K mileage and am pretty sure the coils have never been changed. The rear spark plugs I'm pretty sure have never been changed either. Should I just change the plugs and shift the coils to see if the code goes away (or if the code changes to a different cylinder if it's the coil)? I'm not sure how to test for the other things like pressure etc.
Dad coincidentally drove the car one day and told me the CEL light was on and sometimes blinking. I started the engine today and the light was on with what seemed like a rough idle. Shut off the car and scanned the system pulling up P0303 which apparently is for cylinder 3 misfire.
Car has about 150K mileage and am pretty sure the coils have never been changed. The rear spark plugs I'm pretty sure have never been changed either. Should I just change the plugs and shift the coils to see if the code goes away (or if the code changes to a different cylinder if it's the coil)? I'm not sure how to test for the other things like pressure etc.
03-03-17, 05:05 PM
#2
Moderator
You are overthinking.
Plugs should be changed at 110K miles, so that decision is already made for you.
Unfortunately #3 is the most difficult, so move the coil over to #2/4/6. Check for spark where ever you move it to and if you get good spark, you can install and confirm by actually running the engine.
Salim
Plugs should be changed at 110K miles, so that decision is already made for you.
Unfortunately #3 is the most difficult, so move the coil over to #2/4/6. Check for spark where ever you move it to and if you get good spark, you can install and confirm by actually running the engine.
Salim
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hsmac (03-03-17)
03-03-17, 10:43 PM
#3
Pole Position
Thread Starter
You are overthinking.
Plugs should be changed at 110K miles, so that decision is already made for you.
Unfortunately #3 is the most difficult, so move the coil over to #2/4/6. Check for spark where ever you move it to and if you get good spark, you can install and confirm by actually running the engine.
Salim
Plugs should be changed at 110K miles, so that decision is already made for you.
Unfortunately #3 is the most difficult, so move the coil over to #2/4/6. Check for spark where ever you move it to and if you get good spark, you can install and confirm by actually running the engine.
Salim
03-04-17, 12:13 PM
#4
Moderator
Lay the plug on the engine block with the coil attached.
Ask some one to turn the ignition to start while you observe for the spark. Lot easier if you do it in a shaded or dark environment as the spark would be easy to see. If you have all other plugs installed, then the engine would start running .. so remind your help to keep the start short or turn off the engine. I prefer to do the test with all the plugs removed.
Salim
Ask some one to turn the ignition to start while you observe for the spark. Lot easier if you do it in a shaded or dark environment as the spark would be easy to see. If you have all other plugs installed, then the engine would start running .. so remind your help to keep the start short or turn off the engine. I prefer to do the test with all the plugs removed.
Salim
The following users liked this post:
hsmac (03-05-17)
03-05-17, 04:34 AM
#5
Pole Position
Thread Starter
Lay the plug on the engine block with the coil attached.
Ask some one to turn the ignition to start while you observe for the spark. Lot easier if you do it in a shaded or dark environment as the spark would be easy to see. If you have all other plugs installed, then the engine would start running .. so remind your help to keep the start short or turn off the engine. I prefer to do the test with all the plugs removed.
Salim
Ask some one to turn the ignition to start while you observe for the spark. Lot easier if you do it in a shaded or dark environment as the spark would be easy to see. If you have all other plugs installed, then the engine would start running .. so remind your help to keep the start short or turn off the engine. I prefer to do the test with all the plugs removed.
Salim
03-05-17, 08:47 AM
#6
Moderator
All other test are indicators of a problem. Actual spark is the real functional test. Obviously timing (when the spark is generated) is not tested.
Salim
Salim
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03-07-17, 07:24 AM
#8
Moderator
If you do replace any, do not down grade is the only advice I will share.
Once you do decide to change try to keep the new ones in the back ... it is effort vs convenience. [Do it only if the back ones are already out, other wise you can put in the effort when the back one fails].
Salim
03-09-17, 05:31 PM
#9
Pole Position
Thread Starter
omg I was going to change the plug and check the coil today and the car wasn't there because dad took the car out again. the only thing i did do was check the code and i did notice the strange idling when i turned on the engine. how bad is to drive on the cylinder misfire? i remember a couple years a coil went bad on the road and my car started shaking.
Last edited by hsmac; 03-09-17 at 07:41 PM.
03-09-17, 11:31 PM
#10
Moderator
Flashing CEL -> drive in case of emergency to a safe spot.
Salim
Salim
03-10-17, 06:24 PM
#11
Pole Position
Thread Starter
sigh.. dad said the light was flashing the whole time.
i swapped the coil and scan shows pending code P0301 so it is the coil like i thought. might just change all coils since two went out in the past couple years.
i swapped the coil and scan shows pending code P0301 so it is the coil like i thought. might just change all coils since two went out in the past couple years.
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