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Chrysler Repair/'99 2.5L V-6: code P0301, 0303, 0305


QUESTION: 99 Chrysler Sebring Coupe, 2.5L V6 Mitsubishi motor:  I noticed the last 2 days when my check engine light started flashing, the car seemed like it was chugging and losing speed. I have a misfire that has gone undetected for years. Had the spark plugs, wires, cap replaced last year check engine still stays on.

ANSWER: Hi Danni,
Try your ignition key to get a fault code readout: "on-off-on-off-on and leave on" doing that in 5 seconds or less elapsed time. Then watch the odometer window to see if the mileage reading changes to show a 4-digit number preceded by a P. Let me know what you get.
If that doesn't work then try Autozone where they will often do a fault code readout using a plug-in code reader, for free. Let me know what you find and we'll go from there.

---------- FOLLOW-UP ----------

QUESTION: Hi Roland. I have the following codes: P0300, P0301, P0303 and P0305.

Hi Danni,
The codes are saying that you have miss on cylinders 1,3,5 which are all on the same bank of cylinders. There are many possible causes for a single cylinder miss, but when you have three cylinders missing on the same bank it raises the possibility of a common cause such as a head gasket leak or intake manifold leak on that bank of cylinders (absent any other codes for other possible devices that are also monitored and not showing codes). Have you been loosing coolant as seen by excessive white smoke when you first start from cold, coming from the tail pipe, or do you have to keep adding coolant to the system? You would do well to check the engine compression on those three cylinders to verify that you have at least 100 psi.
You said the distributor cap was replaced, how about the rotor?
Also, look at the wiring of the injector bank on the 1,3,5 side. It may be that the dark green/orange wire that provides the 12v to those injectors is damaged so that those injectors are not working well while the 2,4,6 on the other side are being provided with a solid 12v. So measure and compare the voltage on that specific wire on the two banks of cylinders.
Those are some ideas you might want to look into.
Thanks for the rating. If you rate this answer and also consider clicking on the Yes button to give me a nominiatio for volunteer of the month I would appreciate that.

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Roland Finston


Get a 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.

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I have do-it-yourself experience (50+ years) and a library of 100 1982-2012 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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