How do I fix this?

Casey Bates · Jun 4, 2019

Hey forum,

I have an 5.3L Vortec and I have codes P0171 and P0174 - Lean. I am pressuring the system and hearing a leak here and is audibly differently when manipulating the filler tube. It appears by ACDelco replacements images it twists out.

Obviously it was either trying to be gummed up to stop the leak or caused it. How do I go about fixing this one? Thanks in advance!

Casey

Casey Bates · Jun 4, 2019

Casey Bates said:
It appears by ACDelco replacements images it twists out.”

Looks like it screws left, ya know like everything else. Will try that now. I find it odd that would cause those too lean codes. I assumed fuel pump/filter and/or leak but not there.

Doubeleive · Jun 4, 2019

that's just the pcv line, most likely not the source of your lean code

HiHoeSilver · Jun 5, 2019

Doubeleive said:
that's just the pcv line, most likely not the source of your lean code

I think it's his oil filller tube. And I agree, not the cause of 171&174. It wouldn't be both banks.

Check for leaks in the intake tube /throttle body. You could check for vacuum leaks with carb cleaner, too.

Do you have a scanner to look at freeze frame and live data? This will be the most efficient way to diagnose your trouble.

Doubeleive · Jun 5, 2019

HiHoeSilver said:
I think it's his oil filller tube. And I agree, not the cause of 171&174. It wouldn't be both banks.

Check for leaks in the intake tube /throttle body. You could check for vacuum leaks with carb cleaner, too.

Do you have a scanner to look at freeze frame and live data? This will be the most efficient way to diagnose your trouble.

I think your right on the oil filler

Big Mama · Jun 5, 2019

Mine was a small gap in the intake tube.

swathdiver · Jun 5, 2019

If his intake gaskets are leaking, that will cause a lean condition and the fuel trims will be sky high at idle.

Casey Bates · Jun 6, 2019

So what are normal operating fuel trims on this engine?

Update on the filler tube: it was certainly an issue. Both codes cleared themselves and there is no longer an audible leak coming from the tube. It was cracked at the bottom.

I initiated the test again but it’s still incomplete. I’ve looked up a few other posts getting the system to complete the monitoring test but no luck yet. I’ve driven it 3 or so times both highway and city.

Casey Bates · Jun 6, 2019

HiHoeSilver said:
I think it's his oil filller tube. And I agree, not the cause of 171&174. It wouldn't be both banks.

Check for leaks in the intake tube /throttle body. You could check for vacuum leaks with carb cleaner, too.

Do you have a scanner to look at freeze frame and live data? This will be the most efficient way to diagnose your trouble.

I do but need to find a good post or help from the community on what to look for. My scanner has both freeze frame and live data. It’s an Ancel AD410 specifically.

SnowDrifter · Jun 6, 2019

Filler tube is part of the crank case which is a near ambient pressure system. Wont be part of it.

For lean codes, check intake gaskets, throttle body gasket, egr if equipped, pcv hose from drivers side valve cover to top of intake, purge valve on top of the intake, manifold pressure sensor on top of the intake, pcv tube that goes into the passenger side valve cover, air intake tube + connections post maf (by the air filter), and God forbid your drew the short straw and had a symmetrical exhaust manifold failure, those too.

How do I fix this?

Casey Bates

TYF Newbie

Casey Bates

TYF Newbie

Doubeleive

Wes

HiHoeSilver

Away!

Doubeleive

Wes

Big Mama

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swathdiver

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Casey Bates

TYF Newbie

Casey Bates

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SnowDrifter

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