code p 300 and p303
#1
Registered User
Thread Starter
code p 300 and p303
2003 z with 85000 miles. Took for a spin today and cel started blinking and car started missing. code reader says p300 and p303. I know what the codes mean. Got on web sites and everybody has got a different fix. Some say plugs,coils, injectors. Checking to see what everybody on this site did to fix their's. Thanks.
#2
It could be any if the things you listed. You said you know what the codes mean but just for ease of reading I'll mention it too. P0300 is random/multiple cyl misfire and p0303 is cylinder 3 misfire.
You need to look specifically at cylinder 3 to try to find the problem. Pull the coil out and swap it with cylinder 5 for example. Then clear the codes and go for a drive. If you get p0305 that's a cyl 5 misfire and you know you need to replace that coil.
Check your plugs.
I dont think you can reach the injectors with a stethoscope or a screwdriver up to your ear to hear if the injectors are firing on the vq unless you have an aftermarket Intake manifold. That's the best test I know of with basic tools and the injectors In the car.
Unfortunately the car can't just Come out and say "excuse me, sir, but I have a bad coil in cylinder number 3. Could you please get that fixed?"
You need to look specifically at cylinder 3 to try to find the problem. Pull the coil out and swap it with cylinder 5 for example. Then clear the codes and go for a drive. If you get p0305 that's a cyl 5 misfire and you know you need to replace that coil.
Check your plugs.
I dont think you can reach the injectors with a stethoscope or a screwdriver up to your ear to hear if the injectors are firing on the vq unless you have an aftermarket Intake manifold. That's the best test I know of with basic tools and the injectors In the car.
Unfortunately the car can't just Come out and say "excuse me, sir, but I have a bad coil in cylinder number 3. Could you please get that fixed?"
Last edited by hulkout; 10-15-2015 at 12:44 PM. Reason: Typos
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c.moo (10-18-2015)
#3
Here's some good info on the codes.
0300
http://www.engine-codes.com/codes.php?code=p0300_nissan
0303
http://www.engine-codes.com/codes.php?code=p0303_nissan
0300
http://www.engine-codes.com/codes.php?code=p0300_nissan
0303
http://www.engine-codes.com/codes.php?code=p0303_nissan
Last edited by hulkout; 10-15-2015 at 12:50 PM. Reason: Fix links cuz I always forget to do it right.
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c.moo (10-18-2015)
#4
Registered User
I had this ... I disconnected the battery ( to clear old codes ) moved the " #3 coil pack to 1..... started her back up.... code moved... replaced that coil pack ... done deal.
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c.moo (10-18-2015)
#5
Registered User
Thread Starter
Found oil in spark plug tubes #3 and #5 and around valve cover tube seals. Had new valve covers i got last spring.Just havent had time to change them.Put them on today what a pita.Going to put new plugs in and new coils and check fuel injectors and have them clean. Don't want to do this again for a while.Need to clean intake, it has light coat of oil. When i took valve covers off the inside look clean,no motor honey. Well thanks everybody!
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350zchad (10-18-2015)