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Ask GM Tech (Cam) Your Own Question
GM Tech (Cam)
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 29515
Experience:  GM Grand Master Technician 2007. 14 years experience.
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2005 chevy cobalt: 2.2 showing code p300 and engine is missing at idle

Customer Question

I have a 2005 chevy cobalt 2.2 showing code P0300 and engine is missing at idle.
Submitted: 8 years ago.
Category: Chevy
Expert:  GM Tech (Cam) replied 8 years ago.
WelcomeCustomer There are 2 possible causes. IF the misfire is severe and the engine is shaking badly, I suspect your ignition module may be bad. If so, replace it and the spark plugs. IF the misfire is only a very small one, then you need to start off with is getting your injectors flushed and flow tested. There have been issues with plugged injectors.
Customer: replied 8 years ago.
Okay...I have changed he spark plugs, air filter and cleaned the MAF sensor. The engine light is blinking and the radio locked up on me. Also I test drove the car and the rpms go way up and it take a long time for it to reach 55mph. Two of the spark plugs were smoked black as if it had weak spark and not buring fuel.....What else should I try?
Expert:  GM Tech (Cam) replied 8 years ago.
New spark plugs again AND ignition control module.