SES Light, Bad Gas causing p0325 on new Silverado??

[Ry363]

So this is second time ses light has came on. Says it’s p0325 code (have hypertech programmer) 2018 Silverado 5.3 with only 5,000 miles on the truck now. First happened about 2 months ago on the high way just after I put it to the floor for a few seconds. Think that was on my first tank of shell 87. Anyways, cleared the code and been running chevron 87 until yesterday I filled back up at the same shell, and on my way home from work same thing. Got on the gas and light came on. I would of taken truck into dealer but I have the hypertech installed. Only way to uninstall it you have to clear the code.  

 

Done some research saying it’s better to run 89? Is it a combination of hypertech and maybe the gas at my local shell station? For months now that shell has only carried 87 and it’s also cheaper than any other shell around. What’s your thoughts? Thanks 

[catpartsman]

She’ll is one of the worst gases out there, so I have been told. I have a Diablew tune and have been instructed to run only top tier gas from top tier gas stations. Anytime I run she’ll in my truck, regardless of octane, I get a bad spark knock. When I put Mobil, Marathon, Casey’s, Phillips or so on in she runs fine. I do run 89 octane when available though. My truck doesn’t seem to like the 87 much. I also run a bottle of HEAT in the tank every three or four fill ups too.


Sent from my iPhone using Tapatalk

[silveradosid]

all though you would think shell being top tier gas my truck also runs like crap and get horrible fuel mileage when i use shell

[diyer2]

Before we moved to a small town in the mountains of Colorado I used Costco gasoline exclusively, Top Tier gas.

Costco puts more fuel system cleaners in their gas than the gov. standard.

In 2 years never had an issue.

The local gas station here in the mountains is a Shell station and Top Tier they say.

After about a year of using this gas my truck on a cold start would run really rough for a while.

It also seemed sluggish.

Two treatments with Sea Foam and it was OK.

Here in Colorado our gas is 85, 87, and 91 octane.

They say that due to our altitude higher octane fuel has no advantage.

 

I ran 85 at Costco and 85 at the Shell at first.

The manual says to run 87.

I have used thousands of gallons of 85 octane in our vehicles over the years without any issues until recently with Shell gas.

 

 

[Ry363]

Thanks for the replies guys. Going to run the rest of this Shell gas and fill up else where, and reinstall the hypertech. Also going to try 89 or 91 see if it makes any difference with this truck.

[GMCustomerService]

On 10/20/2018 at 12:32 PM, Ry363 said:

Thanks for the replies guys. Going to run the rest of this Shell gas and fill up else where, and reinstall the hypertech. Also going to try 89 or 91 see if it makes any difference with this truck.

Hi, Ryan. Hope your Silverado is running smoothly. Otherwise, feel free to send me a private message, if you’re considering visiting your servicing GM dealership. Thanks!

 

Anthony J.

[Loco-diablo]

I run Philip 66, 89 or Sunoco 89 pretty exclusively in the 16 months/25k I’ve owned my 5.3.
I will on occasion fill with 93 if my Sunoco grocery store gas discount card gets up to .30/.40 a gallon discount.
I know 87 is the minimum octane, but she seemed a little peppier when I ran mid grade on my first fill up, so that’s what I’ve been using since day 1.
All fuels in my area are E10

I throw a bottle of Lucus injector cleaner in the tank at every oil change.

No fuel related problems so far.


Sent from my iPhone using Tapatalk