Thanks for the tip about changing the spark plugs for damaged coils. I just did plugs on my mom's. I suspect I need to replace coils; it still has a misfire after the tune up. I might want to change the spark plugs again, eh? Thank you.
Thank you! Bought an 03 a few months ago and it's been one thing after another. Everytime it gets wet, rain, car wash, snow, it acted like it wanted to stall out. Today check engine light came on and blinked at me, and it was seriously misfiring. Makes sense after watching this video because it's been raining hard all day. Was seriously about to say screw it an get rid of it. Will give this a try and hopefully this fixes it...yet again lol.
I believe you were pointing to #2. The firing order is 1,5,3,6,2,4 front to back. Also if you look on the plastic cover to the left there it is printed on it.
A weak coil can also cause a misfire but not throw a code. A multimeter ohms test will identify a problem coil. Coils on trailblazers, good quality units, are expensive.
Thanks for the video my trailblazer marks only p0300 cylinders misfired but don’t say exactly the number of the cylinder did u think if I changed to new coils for the 6 cylinder should be ok or i should expect something else than just coil pack thanks
It's tough to say. If you're not getting consistent data for one or two coils, sometimes one not firing can trick the computer into thinking the next cylinder in the firing order missed too. Can you see what cylinders are misfiring currently with a misfire counter?