Misfire in cyl #2, put on new valve gasket, spark plugs, NOW have MULTPLE misfires/PO300?

Question

2004 Chevy Trailblaizer- Originally showed misfire in cylinder #2. Changed Valve Cover Gasket, Changed Spark Plugs, and Replaced 1 Coil thought to be bad. Car still losing power, riding rough, and dying. New code came up-PO300/MULTIPLE misfires now. How is that possible...from 1 Misfire-to now Multiple...after fixing and replacing parts? Please help?!

Answer 1

Hi there,

Here is a list of all possible causes for this code. Sometimes moving the coils can cause issues. 

P0300 CHEVROLET - Cylinder Misfire Detected Random Cylinders

Read more: https://www.autocodes.com/p0300_chevrolet.html