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Cel p0300

telemike

Hummer Enthusiast
Messages
466
Location
Greensboro, NC
My CEL came on while crawling in 4-low. Ran fine on the hour long drive home on the highway. Do you think it had something to do with the engine load at crawl speed or it could be some bad gas that has ethanol in it. I did have to fill up at a station that had ethanol. Maybe some octane boost and gas cleaner? Probably was spark knock.
 

alrock

El Diablo
Staff member
Messages
10,677
Location
Scottsdale
Don't think you need octane boost but a couple thankful with Chevron Techron addictive would be good. Many causes for P0300 and I think you're starting in the right place
 
D

Dennis

Guest
Like Alrock said..could be many things to cause the muliple misfire code..I can recommend something also to consider..you can do your own research..

I use 6oz in every 10 gallons of 100% pure gas of Marvel Mystery oil (I NEVER USE ETHANOIL gasoline)

WDI-465-013R-ZM.jpg
And every 5000 miles, I run a can of this BG 44K on a full tank until almost empty..It's like a dose of penicillin for the engine as one Mercedes service tech once told me.

BG44Klg.jpg
 
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mkmcgreg

Well-Known Member
Messages
196
Location
Carmel
Mine came on on the way to the dealer. Turned out it was the rear o2 sensor going out which caused the system to run lean and misfire. Truck ran fine so now way to really diagnose it. Just another thought I have 76k on it
 

3rdH3

Well-Known Member
Messages
218
Location
Blacksburg, VA
Where do you get 100% gasoline? All of the gas station that I've been at in my area have a sign "may contain up to 10% ethanol"

The Pure stations here in Southwest VA have no ethenol. They were formally marketed as Chevron and Gulf. They recently started using Pure again after about a 25 year absence.
 

ArtHummer

Well-Known Member
Messages
1,220
Location
Gaithersburg/MD
Thanks for the info. But it looks like the closest gas station is one hour away from where I live. But in any way it is good to know that some stations still do sell real pure gas and not the corn additive bs.


BTW. I used BG products for some time and really impressed with with their staff. We used their Fuel/Air Injection Apparatus for a complete clean up of all air and fuel lines.


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with

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and
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