URGENT !!HELP!!!! my silverado 5.3l 2003 code P0300

Flashing means serious or constant misfire, not a small random hiccup misfire. Check your injector connectors, spark plugs, coil packs, and plug wires.
 
so its not the injector because i locked my truck while it was running and there is gas pissing out of the exhaust....


DO YOU GUYS KNOW HOW I CAN SHUT OF TRUCK FROM OUTSIDE DOOR CLOSED LOCK KEYS INSIDE HOOD CLOSED
 
new question is it bad to pull spark plug wired one at a time off a running engine ?

my day is shitty as fuck !!!!!!!!!
 
How you gonna pull plug wires with hood shut? Reach through the wheel wells?

Have gauze on stand by for burnt fingers.
 
How you gonna pull plug wires with hood shut? Reach through the wheel wells?

Have gauze on stand by for burnt fingers.

well it was more of a question of "i already pulled the wires am i an idiot ?" cause yes i reached through the wheel well and pulled them all ...only have small burn on pinky :rolf:

CAA Canadian tow company is going to be here in 2 hours ... i am glad i am nice and warm inside
 
I was told when I was trying to pass inspection the 0300 code would be a vacuum switch is bad. If it detects even a slight variation in vacuum from the normal it reads it as a random misfire.
 
I was told when I was trying to pass inspection the 0300 code would be a vacuum switch is bad. If it detects even a slight variation in vacuum from the normal it reads it as a random misfire.

yeah i am going to do a tune up spark plugs wires run some injector cleaner and then i think replace the evap canister and solenoid (will look into this further) but my truck is misfiring at least one cylinder so ....

the evap code has been the for at least a year now... so i doubt that is the problem
 
gas coming out of the exhaust? injector is stuck open or o-ring is toast. fixitfixitfixitfixit

edit: lol you posted this in the lounge, moved to appropriate section of forum.
 
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gas coming out of the exhaust? injector is stuck open or gasket is toast

couldn't the spark plug just not be sparking on one of the cylinders and it pushing the gas threw the exhaust valve into the exhaust ? and then because the computer detects it not firing it will send more fuel into that cylinder ?

it wasn't like pissing out but there is a ton of black soot where my exhaust exits and it was dripping and smelled like gas :shug:
 
you probably just blew out some carbon buildup, gas smell happens when you run rich or dont get spark which is what this sounds like, swap out the plugs and wires and quit flipping out.
 
you probably just blew out some carbon buildup, gas smell happens when you run rich or dont get spark which is what this sounds like, swap out the plugs and wires and quit flipping out.

i am flippen out !!! i am a noob i though my truck was going to die right before i sold it :tableflip:
 
can you drive it misfiring....yes
Start with plugs, and wiring. If thats not it maybe, you have a coil pack that's at fault however i doubt that.
If not those it could be a injector.
How bad was it misfiring? noticeable or not?



My evap vent SES light been on since 2005... Went into hptuners and turned it off.
They had a recall i believe, they changed it and it came right back on when my dad had the truck... so left it like that never gave me problems.
 
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im dyslexic and might have missed it but did you lock the keys in the truck with it running??
 
can you drive it misfiring....yes
Start with plugs, and wiring. If thats not it maybe, you have a coil pack that's at fault however i doubt that.
If not those it could be a injector.
How bad was it misfiring? noticeable or not?



My evap vent SES light been on since 2005... Went into hptuners and turned it off.
They had a recall i believe, they changed it and it came right back on when my dad had the truck... so left it like that never gave me problems.


it is noticeable at idle for sure will get plugs and order new wires tomorrow

the evap thing i don't care about but if i sell the truck with safety and e-test i will need to get it fixed because the new emission law require that no check engine light is on :facepalm:
 
im dyslexic and might have missed it but did you lock the keys in the truck with it running??

yes i locked the keys in the truck while i was checking out the wires plugs coils and stuff closed the door checked it out was to cold so closed the hood went to door and FUCK it was locked ... waited 30mins then i was like fuck it i am pulling sparkplug wires off.

but this morning tow service came opened truck and boosted it, still running like shit smells like a derby car
 
fuck should have sold the truck a month ago ...some new codes .... ill throw up pics of the codes and the spark plugs


before plugs and wires


after erasing codes and new plugs and wires 15 mins of driving


these are the plug alligned how they came out of the truck ...






apparently i need an intake gasket ... it idles rough like a mofo when i step on it it still has power like it used too i think :shrug:

any idea's ?
 
I believe I'd try a couple new o2 sensors first. Lean banks usually mean an o2 is taking a shit, which is no big deal. Easy to get to and not too expensive either. I'd take it to a parts store and get an actual scan done to see if they can isolate which o2 it is before you go buying all 4
 
I believe I'd try a couple new o2 sensors first. Lean banks usually mean an o2 is taking a shit, which is no big deal. Easy to get to and not too expensive either. I'd take it to a parts store and get an actual scan done to see if they can isolate which o2 it is before you go buying all 4

oh .. ok ill do some more reading before doing anything, thanks for the idea's