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It’s giving a p300 code. Random misfire code and it won’t…

Customer Question
It’s giving a p300...

It’s giving a p300 code

Mechanic's Assistant: Just to clarify, what's the exact code? And have you tried to reset it?

Random misfire code and it won’t stay on at idle

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

99 Sonoma

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

Yes I’ve replaced the fuel filter, fuel pump and spark plugs

Mechanic's Assistant: Anything else you want the mechanic to know before I connect you?

It reads a misfire at 3800 rpms

Submitted: 8 months ago.Category: GMC
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Answered in 2 hours by:
12/14/2017
GMC Mechanic: Chad Farhat, ASE Certified Technician A6 - Electrical / Electronic systems A7 Heating / Air conditioning systems replied 8 months ago
Chad Farhat
Chad Farhat, ASE Certified Technician A6 - Electrical / Electronic systems A7 Heating / Air conditioning systems
Category: GMC
Satisfied Customers: 5,783
Experience: Owner at Carolina Auto Service &Sales , 20 years Experience in Foreign & Domestic vehicles
Verified
The p0300 is random multiple misfire , a low fuel pressuer will cause this but you already changed but the lost common is vacuum leaks around intake manifold,
While running if you spray starting fluid around intake will rpm surges up
Did you replace MAF sensor ?
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GMC Mechanic: Chad Farhat, ASE Certified Technician A6 - Electrical / Electronic systems A7 Heating / Air conditioning systems replied 8 months ago

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