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Ask GM Tech (Cam) Your Own Question
GM Tech (Cam)
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 15201
Experience:  GM Grand Master Technician 2007. 14 years experience.
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I bought a 2004 Chevy Colorado from a friend of mine with

Customer Question

I bought a 2004 Chevy Colorado from a friend of mine with the 3.5 L. Truck ran great but now when I start the truck the engine starts puttering and shaking if I drive it it drives OK but then as soon as I stop at a stop sign or red light the engine starts puttering and shaking again. Code P0300 comes up which is a misfire code. What is wrong with my truck and how do I fix it
Submitted: 3 months ago.
Category: Chevy
Expert:  Marvin the Mechanic replied 3 months ago.

The code P0300 is a misfire code. Need to figure out which cylinder is causing the misfires.

Common problems are spark plugs or coils.

Customer: replied 3 months ago.
I already know what the code means I need to fix the problem so how do I figure out if spark plugs or coils are the issue
Customer: replied 3 months ago.
OK I just change the spark plugs and it seem like it was running a little better so I drove down the Street to the store and it is still puttering and shaking what do I do now
Expert:  Marvin the Mechanic replied 3 months ago.

Do you have a code reader or is it a scan tool? Need to determine which cylinder is causing the misfires. One of the cylinders will have more misfires.

When you changed the spark plugs. Did you notice a line on the outside of the spark plugs?

Vacuum leaks or poor fuel can cause misfires also.

Customer: replied 3 months ago.
You're no. Opt out of my question