2014 Sierra P0172 and P0175

Ricks Munn · December 22, 2018

Hey guys, just wanted to say that I have the same issue with my 2014 silverado as well. I have not yet taken it to a dealership, but I managed to find this video on the internet that I thought was pretty interesting. Unfortunately I do not have a fancy enough scan tool to be able to view all of the PIDs that this guy monitors, but I think this is the problem my truck is having. Basically the truck thinks that it is running fuel that has a really high percentage of alcohol in it (like 35% or so) even though it is standard fuel. The fuel composition sensor needs to be reset and in some cases there is an ECM update that is supposed to correct the problem. Hope this helps you guys. The video is a little on the long side, but very informative.

Here's the link https://www.youtube.com/watch?v=hb4ct0mIV8g

Hillwood · December 22, 2018

Basically same conditions for mine too, 127k miles and got those codes mid March. Then 0430 mid April. I finally narrowed it down to exhaust manifold gasket leak while I was checking the plugs; specifically #8. Ordered gaskets to replace this week and a couple extra bolts.

I think I lost one which is why the leak developed. Dealer said this was a common thing. I said it shouldn’t be if you built trucks to last with good parts and if it’s that common it should be a defect covered under a recall. There’s no reason for bolt heads to be blowing off the exhaust manifold.

It is common.. Think about it.. The temperature swings from hot to cold every time you drive.. The expansion and contraction over time causes the bolts to get weak.. This is normal.

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Firewurx · December 22, 2018

Ya I get it. Shouldn’t happen tho and won’t ever again. I replaced them and traded it after the CEL kept coming back and Chevy straight up told me they didn’t know what was wrong. 3 months with my Tundra now and I don’t know why I ever left Toyota. bye forever Chevy.

Hillwood · December 22, 2018

Ya I get it. Shouldn’t happen tho and won’t ever again. I replaced them and traded it after the CEL kept coming back and Chevy straight up told me they didn’t know what was wrong. 3 months with my Tundra now and I don’t know why I ever left Toyota. bye forever Chevy.

I'm happy for you!

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SS502 · December 23, 2018

10 hours ago, Firewurx said:

Ya I get it. Shouldn’t happen tho and won’t ever again. I replaced them and traded it after the CEL kept coming back and Chevy straight up told me they didn’t know what was wrong. 3 months with my Tundra now and I don’t know why I ever left Toyota. bye forever Chevy.

See ya goodbye...enjoy that cam shaft tower seal leaking...at least you can say that you used to drive a Chevy ?

Diverjer · May 29, 2019

Yes I got the P0172 P0175 and haven't had the truck 24 hours. It has 49,500 miles on the 5.3.

Colossus · May 31, 2019

On 12/23/2018 at 12:28 AM, SS502 said:

See ya goodbye...enjoy that cam shaft tower seal leaking...at least you can say that you used to drive a Chevy ?

Oh let him live in his "Oh what a Feeling" moment.

Burban15 · June 11, 2019

Same here, 2015 Suburban, same codes come and go at will. Car has 175000 miles.

Burban15 · June 11, 2019

On 5/29/2019 at 2:57 PM, Diverjer said:

Yes I got the P0172 P0175 and haven't had the truck 24 hours. It has 49,500 miles on the 5.3.

You just bought it?

Diverjer · June 11, 2019

Yes, dealership checked it out and kept it several days while a part was ordered and put on. When I picked it up, nobody that was there knew what part was put on, manager was gone. Next time I am there I will ask, but so far it has not thrown anymore codes.

mchnhd4 · June 11, 2019

On 9/4/2018 at 8:13 AM, BAMA 4x4 said:

Anybody else dealing with these issues?

Exact same issues here just started for me. Same codes and everything. I started a thread a couple days ago on this. Dealer diagnosed is potentially as a PIP5590A and points to the high pressure fuel pump. That is a $1250 fix though and they didn't feel 100% confident about it. Mine seems to happen when the truck is idling in hot weather. Hard shifts are because the truck is going into fault mode. Everyone I talk to is saying its more likely the injectors. After seeing that other poster say he got the injectors cleaned and it seems to be fine I am on the verge of doing that also. Truck has 65k on it and its a 2014 5.3

CoachGardnerFHS · June 26, 2019

2014 5.3 Silverado. Same thing, except most on here say it happens around 125K mine did it about 6 months ago at 63K, cleared itself, then came up again yesterday at 69K. I commented to my wife that both instances were days with a lot of idling, then came here to see much of the same. With mine being under 100K, is this something that should be under warranty?

zzach19 · August 11, 2019

I have a 2014 Silverado 5.3 with 65k miles. I started getting the P0172 and P0175 codes about two months ago. I cleared them pretty quickly each time the light popped on and determined that they would reoccur after I would remote start it and let it run for 5 minutes or more. I really do believe this issue is triggered, at least for me, by idling at least 5 minutes. When I intentionally avoided idling the codes did not reappear. After searching this and other forums I decided to focus on the injectors. After a bit of research I settled on trying a fuel injector cleaner, Liqui Moly Jectron to be specific. I usually don't have high expectations for the "off the shelf magic bullet" but this stuff has me really optimistic. I put it in two weeks ago with about 2/3 of a tank and drove about 200 miles over the next day. Since then I have let it idle over 5 minutes two or three times with the key on and exactly 10 minutes three other times by remote starting it and letting shut itself off. At this point the light has not come back on yet. I am sharing this so that others can give it a try and see if they have similar results. The best part being the cleaner is less than $10 at my local Autozone. If this continues to keep the code cleared I am going to add it to my every second oil change checklist. If any of y'all give it try please post here and let me know if it helps at all. I'll report back if it keeps working for me.

mchnhd4 · August 16, 2019

On 8/11/2019 at 3:34 PM, zzach19 said:

I have a 2014 Silverado 5.3 with 65k miles. I started getting the P0172 and P0175 codes about two months ago. I cleared them pretty quickly each time the light popped on and determined that they would reoccur after I would remote start it and let it run for 5 minutes or more. I really do believe this issue is triggered, at least for me, by idling at least 5 minutes. When I intentionally avoided idling the codes did not reappear. After searching this and other forums I decided to focus on the injectors. After a bit of research I settled on trying a fuel injector cleaner, Liqui Moly Jectron to be specific. I usually don't have high expectations for the "off the shelf magic bullet" but this stuff has me really optimistic. I put it in two weeks ago with about 2/3 of a tank and drove about 200 miles over the next day. Since then I have let it idle over 5 minutes two or three times with the key on and exactly 10 minutes three other times by remote starting it and letting shut itself off. At this point the light has not come back on yet. I am sharing this so that others can give it a try and see if they have similar results. The best part being the cleaner is less than $10 at my local Autozone. If this continues to keep the code cleared I am going to add it to my every second oil change checklist. If any of y'all give it try please post here and let me know if it helps at all. I'll report back if it keeps working for me.

I did the same thing. Ran 2 bottles in 2 tank refills. Also ran shell Vpower thinking it might be a fuel problem; cuz it only happened when it was hot outside (85+). It came back a couple weeks later. Decided to trust the dealer's diagnosis and pay up $1300 for a hpfp and it's been good ever since. Still gets a little rough on idle when its really hot and idling for a couple minutes but no check engine light or driveability issues.

Tech43 · September 2, 2019

On 8/20/2018 at 10:24 AM, BAMA 4x4 said:

Any luck with fixing P0172 and P0175? I am having the same issues with my 2014 Silverado 5.3 with 128k miles. I have changed the MAF and MAP. The check engine light may stay off a day or two when cleared. Fuel pump leaking fuel in crank case? Worked on one every shop in town tried to fix. Put fuel pump on fixed gdi motor 5.3 L83