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Its misfiring and the code is p300. No it runs rough at

Customer Question
Its misfiring and the...

Its misfiring and the code is p300

Mechanic's Assistant: Have you seen the misfire code before? Has the car been stalling?

No it runs rough at times it seems to want to cut off at times

Mechanic's Assistant: What is the model/year of your Toyota?

Avalon 2006

Mechanic's Assistant: Are you fixing your Avalon yourself? What have you tried so far?

When it started i had the spark plugs replaced but know i think it may be the coils

Submitted: 3 months ago.Category: Toyota
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Answered in 5 minutes by:
3/23/2018
Toyota Mechanic: carguy1, auto technician replied 3 months ago
carguy1
carguy1, auto technician
Category: Toyota
Satisfied Customers: 27,497
Experience: 25 Years experience all makes and models.Nissan factory trained,Certified Subaru Tech
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Toyota Mechanic: carguy1, auto technician replied 3 months ago

So I am clear, the car isn't misfiring all the time?

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Toyota Mechanic: carguy1, auto technician replied 3 months ago

This is a tricky code because basically, the computer cannot determine which cylinder is misfiring. So, you would have to replace all the ignition coils. What I do see sometimes is a faulty mass air flow sensor causing this issue. If the car isn't misfiring all the time, then this could be the problem. It changes the fuel mixture so the engine could be starving for fuel at sometimes. It's also possible it could be running to rich. This will cause this code to happen without setting a code for the mass air flow sensor.

Please let me know if there is anything else I can do to help.
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