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14 Silverado 5.3
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3 Posts
Discussion Starter · #1 ·
Hey guys, thanks for taking a look and helping me out.

My '14 Silverado 5.3L Flex Fuel has had rough cold starts, smell of gasoline, and now engine codes. It is a Flex Fuel Engine.

The P0172 and P0175 Codes are Rich condition on Bank 1 and 2. The P0454 Code I believe is fuel pressure issue.

The gas smell tells me there's an actual leak, which is affecting the fuel pressure when the truck has been sitting, which would explain the rough cold start as the fuel pump rebuilds pressure.

My question is what's the most likely source of the problem. The High Pressure Fuel Pump on the engine or the fuel pump in the tank? I really don't want to take the truck in, if I know what needs to be replaced there's enough info online to get the job done. Just not sure where to focus my efforts.

I also think the Lack of Fuel Pressure has messed up the flex fuel system and the rich condition is being caused by the engine essentially thinking it has E85 in it or something.

Am I on the right track? Any help would be greatly appreciated.
 

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2021 Trail Boss LT L84 10L90
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287 Posts
P0454 is a problem with the EVAP pressure sensor, nothing to do with fuel pressure.

Your rich codes and cold start problem may be a wrong calculated alcohol content. If you never run E85 and the alcohol content shows over 10% on a scanner, it needs to be reset with a scantool.

I believe there is a reflash available for the calculated alcohol content
 

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14 Silverado 5.3
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3 Posts
Discussion Starter · #3 ·
Thank you so much for your response.
Would the EVAP sensor cause the gas smell. Or the rich condition ? The gas smell lead me to believe it was an actual leak and not just a sensor:
 

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2004 Sierra 3500 6.0L, auto, extended cab, cab&chassis, upgraded to 4wd
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632 Posts
If an evap line has broken, that would give off a gas smell around the truck. It's unlikely to cause a rich condition in the engine.
 
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