2005 Taurus stubborn p0300

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2005 Taurus stubborn p0300

Unread post by davidkien68 » Mon Jan 12, 2015 11:03 am

I have a 04 Taurus with a vin U 3.0 that sets a p0300 while sitting still idling in Park. With a snap on Solus Pro scanner I can see the misfire count go up 1 to 2 counts about every ten seconds. The car seems to idle fine and seems to count misfires faster if the a/c is off and will not count any if it is in gear. If I watch the cylinder contribution numbers it seems to catch a problem with every cylinder but very random as far as time and which cylinder, The plugs are fairly new and coil and wires check ok but I really don't think it is ignition related just by the way it acts. The fuel trims are around 1-3 the labscope pattern of the crank sensor looks very normal and I replaced both the cam sensor and the synchronizer with no change. I tried finding a vacuum leak by spraying carb clean around while watching O2 readings with no luck and removed and plugged pcv line which made no difference. The customer said that this seemed to start shortly after he had oil changed at a quick lube facility. I see there is a 10 year old Ford bulletin on a software update for a p0300 but it seems unlikely that it has taken it this long to just now show up. I might try cleaning the injectors next but am open for any ideas This has been going on for multiple tanks of fuel now. Thanks in advance for any thoughts and help.


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Re: 2005 Taurus stubborn p0300

Unread post by carriedi » Mon Jan 12, 2015 10:44 pm

injector cleaning would make sense to me. I have seen multiple vehicles that have slight random misfires and doing an injector cleaning (motor vac) cleared up the condition.
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