# P0300 and shake a lot sometimes



## bobyang (Mar 22, 2012)

Car:
Nissan Sentra SE-R 2.5 year 2003, 31k miles

what I have done:
-change spark plugs 2 weeks ago

Situation:
6 weeks ago, my car SOMETIMES shakes a lot while idle (traffic light, stop sign), but it goes, the Service Light never came up.

2 weeks ago, it shakes again, and for longer time (about 6 minutes in the traffic jam, very slow), at the same time "service light" was flashing and then stay. after 6 minutes, the car is back to normal and light is on. I check the code which is *P0300*. Then, I took it to the shop to get fix, they change the spark plugs for me. It was ok when I drove to them, so I cannot really see the difference.

while driving in the past 2 weeks, shake happens about 1 second SOMETIMES (only twice) at the traffic light.

This morning was ok all the way when I am out of the house. I can feel shaking and less power 2 minutes after getting on the freeway the Serice Light went on, and only when I speed up about 52m/h (above 2300RPM) and not so shaking if I drove slower and shake a lot while idle waiting for the red light. However, it went back to normal again afterwards before I park my car. I did a test run after an hour and it is still fine.


Any suggestion? or any following makes more sense to you about SOMETIMES it happens at speed 0mh or above 50mh? For example, will Vacuum Leak only happens sometimes at stop sign?


reference: http://www.obd-codes.com/p0300
-Vacuum leak
-Faulty Spark Plugs or wires
-Faulty Coil
-Faulty oxygen sensor
-Faulty Fuel Injector
-Burned exhaust valve
-Faulty catalytic converter
-stuck/blocked EGR valve/passages
-Faulty Camshaft position sensor
-Defective computer



thanks!


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## SPEEDO (Jun 9, 2003)

pull the spark plugs and see if the electrode is smashed.. or any little dents on it, if the screws for the butterfly valves have not been loctited, you may have lost one or... and its bouncing around in your cylinder...


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## bobyang (Mar 22, 2012)

SPEEDO said:


> pull the spark plugs and see if the electrode is smashed.. or any little dents on it, if the screws for the butterfly valves have not been loctited, you may have lost one or... and its bouncing around in your cylinder...


thanks! but I just replaced them 2 weeks ago in the shop... I think they should be ok?


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## SPEEDO (Jun 9, 2003)

did you notice the color of the plugs? might have a head gskt issue...


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