2003 4.2L Trail blazer P0300 Random m...

2003 4.2L Trail blazer P0300 Random misfire

Posted in the Chevrolet TrailBlazer Forum


Greenville, SC

#1 Sep 10, 2010
Started with P0305 code, replaced the spark plugs and then the #5 coil. Code changed to P0302. Replaced #2 coil and the fuel filter. Runs a lot better but now have P0300 random misfire code. The code only comes up going up hill, no light when engine is idling. What next???

Arbil, Iraq

#2 Nov 2, 2010
your problem is the catalatic converter

Ewa Beach, HI

#3 Dec 18, 2011
i had low compression on cyl 3 found out it had a burnt valve,removed the headhadit machined reassemble everything. upon first start up i had low idle and misfire #5 cyl,switched #5 with #4 and runs a little better but now gives a p0300 random misfire. any ideas ???

Waldorf, MD

#4 May 28, 2014
misfire and smell gas
#5 Apr 4, 2015
04 trailblazer it all started when I ran out of gas when I started it back up it missed light flashing p 300 code replaced a coil and new plugs and cleaned injecters..still missing idk what is wrong.

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