Question

P0300 Continues to come on nearly at every trip (short or long trip) .I've Replaced Fuel-pump,Fuel-reg'-fuel-pump-relay,fuel -filter,Spark-plugs,Ignition wires,All Coils,PVC-valve,Battery,Air-filter,All 4 Oxygen Sensors,fuel cap,thermostat & Thermostat housing,Parts totally around $5000,but not all related to engine...I changed all oils & fluids & filters on 2000 5.3L SILVERADO With the very best available,All the above mentioned parts are replaced with either AC/DELCO OR DELPHI FACTORY parts..."Still plagued by this code "P0300" ???
I REALLY DON'T WANT to replace the WHOLE truck till I accidentally fix it...I'm a poor person and can't afford to keep doing The "PROCESS OF ELIMINATION" Till found...And have
more money in this truck then it's worth,Also it's my only means of transportation being Disabled ,
I need it for Doctors appointments etc...PLEASE-PLEASE HELP ME !!!
GOD BLESS YOU AND THANKS TO ALL FOR ANY ADVICE ...

Answer 1

P0300 Random misfire

Random misfire code on Chevy products are either easy to pin point or difficult, Some of the main cause for Random mifire that go untested are plugged exhuast system, You can get a random misfire that is cause by a plugged catalytic and not have a catalytic code condition , The best way to find a random misfire on a Chevy product is with a ignition analyzer, This year vehicle and VIN T some came with Distributor caps and some with Coil near plug style.Ignition analyzer is the best way to trouble shoot this code condition.

Here is a sparkplug that cause a P0300, it did not code a particular cylinder just a random misfire with a hesitation at load, A ignition analyzer was used, and pin pointed the exact cylinder which recently had  a tune up and a broken sparkplug shell and went unnoticed. It only coded a P0300. On a 2001 5.3.

 

 

 Here is a new distributor that was installed on a vehicle , Being OEM , AC delco, it was never suspected of causing a P0300. until the the throttle body cover blew apart.

 The distributor cap shorted between cylinder 2 and cylinder 8 which touched each other in the distributor cap.