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Dan, Technician
Category: Chevy
Satisfied Customers: 23473
Experience:  Independent Shop Experience, 2 Year Automotive Diploma, & Access to Information Database
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2003 Sliverado, rough idle in cold weather..Mass Airflow sensor

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2003 Sliverado, rough idle in cold weather. code 0300. Replaced Mass Airflow sensor, no change. It only seems to happen in weather below 18 degrees

Welcome to JustAnswer, my name is XXXXX XXXXX I'm here to help get your problem resolved. Ask follow up questions, thanks.


It souns like you have a intake gasket problem. When the engine is cold and missing, run water over the intake manifold and check for an RPM change. If a change is noted, replace the intake manifold gaskets and check the manifold for warpage. Let me know if you have questions, thanks.

Customer: replied 5 years ago.

I get a 0300 code mis fire. I was going to run BG fule injector cleaner. Should I try the manifold test first?


Ya, I dont think its a fuel injector problem......Thats not usually effected by temp and woudl only cause a specific cylinder to misfire. Let me know if you have questions, thanks.
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