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 reade…
Chevy Trailblazer misfire DIY diagnosis – step one – p0301 p0302 p0303 p0304 p0305 p0306
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Thanks much – me and my 2002 TB just benefited from this (first the
blinking Service Engine Soon / running lousy) then the P0304 code (cylinder
4), Swapped with 2 (and new plug in 4, re-started and Cylinder 2 misfire.
$80 later and one coil pack all good. Couldn’t have been more direct.
Nice VID…
Dealer and Private mechanic replaced all plugs, #2 coil, cleaned all
injectors, replaced gasket around coils (GM said ?water may get down plug
hole) and I still got a P0302 after one month…
Any ideas?
Like for the outtakes at the end. hahaha
I have a misfire in cylinder 1 and have changed all of my sparkplugs. My
TB is still running rough. I dont have a code reader, should I go ahead and
chande my Coil (75.00)? I have one at tke house. If this doesnt work, then
I need to change the fuel injector (135.00), Correct????
mayo …so how do i go bout fxn a p0300 i replaced coil six and all s/plugs
i purchased a code reader first code was a misfire on # 6 so coil replaced
cleared codes and now i have a p0300 (random misfires)
Also the throttle body is moist with gas and I just cleaned it about a
month ago
True that! I’ve stocked up on low mileage coils from ebay. I think the
delphis are going for around $80 each new. So $80/coil x 6 coils = not
going to happen lol
The scan tool that I have is the Vetronix Tech2. The latest part number is
OTC-3649. I have it because I have to be able to diagnose and repair
anything in a modern GM truck/suv. It is nice and all that but for you guys
working at home it isn’t really necessary.
Awesome thank you x1000000
very nice. I just took my 03 trailblazer to the dealership. They charged
120 for the diagonistics, and wanted to charge me $510 just to replace one
coil. half an hour and a few tools later, I did it myself for $100 in parts.
What kind of OB2 code reader is that (make/model/etc). I have a small one
but want to upgrade to something like the one you showed. Thx
I have a p0300 code i replaced all the spark plugs and i had a p0340 so i
replaced the cam shaft sensor and i have no more p0340 but still a p0300
and it runs like crap
Thanks for the vid. Had a couple misfires. Got 303 and 301 at different
times from Autozone. changed #3 plug then had only 301. Changed all plugs
and still had 301. Bit the bullet and bought the coil and hot damn the
thing is peppy now. I also watched your vid for cleaning the throttle body
and did that in the process. Great info!
i meant it threw po300 after i cleared the po303 code.
What scan tool u got
Good deal, po455 any ideal
@toortiss All that work? We didn’t even do the compression test, fuel
injector test, or leakdown test yet. An ignition fault is the most common,
that’s why it’s the only one up (for now). Shops around here charge
$70-$100/hr for the same thing that these guys can do in their driveway. On
second thought, it’s not “can do”, it’s “are doing”.
@Adam rosario check fuel pressure. Also check the injectors on cyl#3. Last
do a compression test on that cylinder.
@MAY03LT Order smoke machine Tuesday. Any trans problem yet.
very very helpful video. im gonna try to fix my 03 trialblazer with 150k
tonight. it was throwing po303 until i cleared the code then it threw
po303. any ideas why?
Great thanks. Also (if you know) my OB2 doesn’t work on my Trailblazer but
works on other cars. You think that’s a fuse problem or the attachment
itself. It seems to only have a couple pins on the top and bottom, not sure
if it must have all 16 or so pins (if so then obviously that is the
problem). Do you happen to know what that is called? It’s the connection
attached to the truck that the OB2 plugs in to. Anyone’s help would be
greatly appreciated!
@MAY03LT Ok so how many of these people are going to have those tools? I
don’t know anyone who owns a scan tool let alone a compression tester or
leakdown tool. And once again you are making it sound like dealer is out to
screw everyone. I can assure you that that is not the case.
A very good explanation. I have a basic generic code reader, and I can’t
afford a Verus or Modis, but I would like to upgrade to get real time data
with various common manufacturers. What do you think about Auto Enginuity?
@MrNeoluke That is a Tech 2 scan tool. The only other tool that I know
reads live misfire data in GMs is the Snap On Modis. There very well may be
others though.
@blackericdenice There are too many possibilities to even guess. I’ve seen
cases where it was caused by: a bad purge solenoid, bad vent valve, bad gas
cap, leaking canister, cracked lines, leaking from fuel tank, bad FTP
sensor, and even leaking from the rollover valve. Without a good scan tool
and a smoke machine, you’re limited to visual inspections.
Good.. i’ll be watching to see if you can fix my issue with my heater only
blowing hot air out of the passenger side of the truck… the driver side
is cold as hell… I think there may be a “door” or something stuck in
there.. im not sure how it works
Good video, but you mis-stated something here. You said: if after swapping
the suspect coil and plug with those from other cylinders, and the misfire
continues to affect the original cylinder, then you can rule out an
ignition problem. You made no mention of an ignition fault possibly lying
in the coil primary circuit or a driver failure within the ecu. An ignition
system is comprised of many more components than just the coil and plug.