p0300 code
Thread Starter
Cruising
Joined: Jan 2011
Posts: 12
Likes: 0
From: Mukilteo Washington
p0300 code
Anyone out there that can give me any info, on my '99> been idling really rough lately, exhaust tips are black with soot, check engine light came on yesterday-code was p0300. Seems to run alright, though the gas mileage has suffered a bit lately.
Tech Contributor
Joined: Dec 2006
Posts: 10,962
Likes: 29
From: Van Buren Arkansas
Wounded Warrior Escort '11
Always start by pulling your codes using the DIC. Its a powerful tool built into the car and its FREE! Were there any other codes? If that was the only one, start by checking all of your spark plug leads and insure they are on tightly. Also check the ground wire on the rear of the driver's side head.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
P0300 is a cylinder miss. Your plugs and wires are always the first things to check. When was the last time that they were changed and are they in good condition???? You should remove each one and check the contacts inside the boors for damage/corrosion, check the insulation on the wires and boots and then check the resistance of each wire. A good wire will read 275-750 OHMS
Change the plugs with new irridums
Make SURE that the boots are properly connected to the coil tower and the plugs.
Examine the engine running at night and see if you can hear or see arcing when the engine is running in the dark/
If the wires are bad,, the GM Performance RED wire are some of the BEST you can buy. Contact Gene Culley www.gmpartshouse.com for a great price on wires.
BC
Change the plugs with new irridums
Make SURE that the boots are properly connected to the coil tower and the plugs.
Examine the engine running at night and see if you can hear or see arcing when the engine is running in the dark/
If the wires are bad,, the GM Performance RED wire are some of the BEST you can buy. Contact Gene Culley www.gmpartshouse.com for a great price on wires.
BC
Last edited by Bill Curlee; Nov 25, 2011 at 07:36 PM.
