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Chrysler Repair/P0300 AND P0306 ENGINE CODES

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Expert: - 8/3/2011


Question
Hello Roland, I found your advice in the past to be spot on.  I have the same 2000 Chrysler 300m that has the trans problem back in 2006.  Now I have the above codes.  p0300 and p0306.  The car has no power on hills unless I down shift.  Thank you in advance.

Answer
Hi Marc,
The codes mean a single cylinder misfire (0306 means #6) and multiple cylinders misfiring. There are many pssible causes unfortunately:
fuel pump or filter (unlikely as regards the filter), injector harness connectors, ignition coils circuits, spark plugs, mechanical problem (but compression test would probably show that), contaminated fuel, water in fuel, pcm power ground connection (by the rear of the left headlamp housing), injectors, restricted exhaust, intake restriction, the pcm itself, the evap emission control system, the exhaust gas recirculation valve system (this is something I would certainly recommend that be checked, as if the valve sticks ajar it will definitely cause misfiring), other mechanical (?), and damaged trigger wheel (something to do with one of the engine postion sensors such as that of the crankshaft (?)). The parenthetical items are my remarks.
Many of these also might set a separate code, such as 0306.  But the egr valve would be high on my list as would the ground connection for the PCM.
Let me know how this progresses, please.
Roland  

Chrysler Repair

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Roland Finston

Expertise

I specialize in Chrysler/Dodge/Plymouth cars, minivans, and SUV's for the model years 1982-2008 based upon my 50-year DIY experience, factory shop manuals and wiring diagrams. I offer fast repair advice to help you minimize repair costs by helping you diagnose and do it yourself. Problems with electronically controlled engines and transmissions as well as body wiring problems are my specialty.

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Five decades as a 'do-it-yourselfer' on domestic and imported cars

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Yahoo Autos Group called The Chrysler Lebaron Club (co-moderator)

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Degrees in Physics/bruised knuckles.

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"Top expert of 2010" and "2011" at Allexperts. Among top 50 experts for years 2006-2009 at Allexperts.

Quickest "average response time" at Allexperts (currently no. 1).

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