Chrysler Repair/Bad egr?


QUESTION: Hi Roland,

I have a 2006 Chrysler 300CAWD 5.7 Hemi. My car wouldn't start one day and since then I've been having problems. No symptoms up to the day it wouldn't start. I finally got it started, but loud knocking and very hard idling. I haven't drove it far distances because it dies at low speeds or when I stop. It doesn't die if I leave it in park but idels very rough. Check engine light came on and codes were P0300 and P0306. I changed all spark plugs yesterday but still having same problem. My next step was to change the coil packs but 8 coil packs at $30 and not knowing that's the problem for sure kinda bothers me. Could it be my egr? It's $40 and seems easy to replace but don't want to bother if its not that either. Any advice would be great

ANSWER: Hi Jamie,
I would say with no codes that the egr might be suspect for hard starting and poor idling. But with the specific codes I believe that a focus on the 'miss' on cyl 6 would be a better approach. It might be a fuel injector not working on that cylinder or a mechanical problem which you could check first by removing the spark plug an checking the compression. By loud knocking do you mean it sounds to be mechanical interferenced of some sort? An egr valve sticking slightly ajar will cause a fuel/air mixture problem, but not typically knocking per se. But let me check the shop manual and get back with any further suggestions for the 306 code, later today.
PS Please 'rate' my answer (aee below).

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QUESTION: I'm sorry I should have specified the knocking has since stopped. It was just that first day when I couldn't get it started, it knocked after I got it started. Also after changing spark plugs do I have to clear the engine light and see if it comes back with same codes, or does that reset itself? Thanks again

ANSWER: Disconnecting the battery for a minute will usually clear the codes. Then drive it again and see if they return. I revised my first answer, also.

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QUESTION: Thanks so much!!

Hi Jamie,
Would you try the code erase, drive it again until the  check engine light comes on again, and verify that the code is still 0306? Then let me know. Because it takes me probably a half hour to copy and send 10 pages I would like to be sure that the code is still there. Thanks,

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Roland Finston


Free fast answer to your repair question about a Chrysler/Dodge/Plymouth car, minivan, SUV, or truck. Problems with electronically controlled engines and transmissions as well as body wiring problems are my specialty. This free troubleshoot advice forum helps you diagnose faults, minimize repair costs or do-it-yourself.

I answer questions seven days a week and respond to you in about 30 minutes. "Maxed Out" means I am answering another question, briefly unavailable, or asleep overnight, so try again later.

I have do-it-yourself experience (50+ years) and a library of 100 1982-2011 Chrysler factory shop manuals and 20 multi-manual Chrysler Corp. CD's.

I was voted "Top Expert" 2010-2015, here at AllExperts, and have answered 20,000+ questions.


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

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

Advanced degrees in Physics/bruised knuckles

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"Top expert" of 2010, 2011, 2012, 2013, 2014 and 2015 here at Allexperts. Quickest "average response time" at Allexperts (currently no. 1).

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