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Its misfiring I ran a diagnostics test and it came up P0300…

Customer Question
Its misfiring I ran...

Its misfiring I ran a diagnostics test and it came up P0300 I have changed the plugs wires and all 3 coil packs but its still misfiring

Mechanic's Assistant: How many miles are on the car? Is it a steady misfire? Or random?

Its a steady misfire its just running rough no power up hill it has172000 miles on it

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

06 pontiac grand prix

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

Yes im doing it myself and ive changed the plugs and wires and coil packs

Submitted: 5 months ago.Category: Car
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Answered in 6 minutes by:
3/19/2018
Auto Mechanic: Mechanic01, ASE Certified Technician replied 5 months ago
Mechanic01
Mechanic01, ASE Certified Technician
Category: Car
Satisfied Customers: 3,780
Experience: Owner at Baltic investments
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Hello my name is ***** ***** welcome to just answers! I will be assisting you with all of your vehicle questions today. Give me one moment while I review your question and come back with a answer. Please be aware I do not know your skill level or abilities so I will be asking a lot of questions and in a lot of cases we will respond to each other quite a lot before we find a solution. As far as phone calls are concerned that is the system prompting you, not me, and they do cost more money, I prefer text but in some cases a phone call is required. If I don’t answer right away or quickly in conversation I am helping another customer or have stepped out for a moment and will respond as soon as I can. Ok lets get started!

have you checked actual spark yet?

Have you checked injector pulse with a noid light?

Havr you done a compression test on the cylinders ?

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Customer reply replied 5 months ago
No I just was doing what they told me when diagnostic was ran the car runs its just skipping bad and no power up hill
Auto Mechanic: Mechanic01, ASE Certified Technician replied 5 months ago

ok we need to do those tests next

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