Chevy Trailblazer misfire DIY diagnosis - step one - p0301 p0302 p0303 p0304 p0305 p0306
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.
How to find a misfire without a scanner 2
Scanners are great tools, but sometimes they aren't any help. That's when
understanding the system, and how to test it is all you have. Here are
some ways to find the problem
Trailblazer check engine light on - reading codes and other fun facts
This is the most frequent question that folks axe me about. So, I went out
and bought two budget friendly code readers to show you the first things to
do when the check engine light comes on.
The first code reader is the ELM327 (made by BAFX). You use this with an
android phone, along with the torque app. This unit communicates with the
phone wirelessly over bluetooth.
The second reader is the actron cp9125. No phone required.
I bought both of those tools from amazon. They had the best price.
The last tool is my GM scan tool. I showed this only to prove that the
cheaper tools will pull the same codes that the GM tool does.
How to identify a bad main relay on a Honda (PGM-FI)
1999 Honda Accord No Start (case study)
For more on Engine Performance Diagnostics go to my website at
I am doing field work in this video on a 1999 Honda Accord with an
intermittent no start complaint. Other symptoms include: stalling, long
crank times, surging, bucking, poor transmission shifting.