Chevy Trailblazer misfire DIY diagnosis - step one - p0301 p0302 p0303 p0304 p0305 p0306

Опубликовано: 01 Апрель 2026
на канале: MAY03LT
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Here I have a Chevy Trailblazer with a P0302 - cylinder #2 misfire. I show you the basic troubleshooting steps that you can do that only require a code reader and a few hand tools. This procedure can be done regardless of which cylinder is misfiring.

First, I swap the coil of the misfiring cylinder with another cylinder. At the same time, I swap the plug of the misfiring cylinder with another cylinder that is NOT the one that I swapped coils with.

I then clear the codes and then run the engine. If the misfire moves to the cylinder that I swapped coils with, then I have a bad coil. If the misfire moves to the cylinder that I swapped plugs with, then I have a bad plug. If the misfire stays on the same cylinder, the problem lies elsewhere. Further steps will be shown in future videos.

Big thanks to Bill (Kristis Dad) from trailvoy for donating the bad coil!!!

UPDATE June 2013 - I know you can also unplug the coils with the engine running to isolate the cylinder. If you want to show that to these guys, how bout YOU make a video. When the average youtube user, who doesn't have much experience doing stuff like that, gets hurt, YOU can live with that on your conscience. I know I couldn't. SMFH.