Elusive p0171 and p0174 problems

[ryankokesh]

I wasn't too worried when these guys popped up on my code reader. Easy fix, I thought... replace an intake boot and you're good to go! Well, two boots and a bunch of other stuff later and the codes are still there. The code reader (I'm using Torque for this on an Android) even calls them "current" faults and they don't go away at all when cleared. From what I've been reading, it seems that normally people's CEL will go off for a short time when the codes are cleared.

So here's a list of stuff that I know isn't the problem:

• Lower and upper intake boots replaced (there was a small rip in the lower, but the upper appeared fine)
• MAF cleaned
• Entire CCV system replaced
• Intake boot "F" connector replaced
• Oil cap is tight and appears to seal well
• Fuel pump replaced with OEM a few months ago
• Fuel filter has around 40k on it, so technically not due yet
• DISA rebuilt last year (including a new seal)
• VCG replaced when I did the Vanos two years ago

Anyone got any ideas? This is driving me up the wall....

[danewilson77]

You haven't replaced the dipstick tube yet! That has to be it. SAP? Throttle Body gasket?

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[ryankokesh]

You haven't replaced the dipstick tube yet! That has to be it. SAP? Throttle Body gasket?

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Hmmm, I didn't really think about the SAP... I'll have to check that!

The dipstick tube wasn't replaced, but I cleaned it and put a new gasket on it. Thinking that should be enough? I do still have to find the stupid new one. What kind of person loses a freaking dipstick?

And I forgot to mention I put in a new throttle body gasket when I did the CCV. Although the old one looked like it was in pretty good shape.

[danewilson77]

Sounds good. You should have this fixed by now. I thought you were Seth's mechanic!?

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[ryankokesh]

I thought you were Seth's mechanic!?

If you think about it, that explains a lot, doesn't it?

[danewilson77]

If you think about it, that explains a lot, doesn't it?

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[derbo]

if you think about it, that explains a lot, doesn't it?

roflmao

[LivesNearCostco]

Last time I had one of these codes, I found my F-connector was not inserted into the upper intake boot! If you think oil dipstick is sucking air but you replaced the lower O-ring, could check that the dipstick itself has the two small O-rings at the top under the plastic pull ring. It may also be possible for the DISA to leak even with new flap and new O-ring, if it leaks air at the vacuum bulb.

Could do a smoke test with mechanic or spray the starting fluid/cleaner around the intake manifold while running to look for vacuum leaks. There are at least 3 or 4 vacuum hoses running around and connected to the intake manifold somewhere, so having any of them disconnected could cause this. Two connect to the F-connector so might track where they go to make sure they're connected on the other end. When you replaced the CCV, you replaced all 4 related hoses including the one on the intake air equalizer thingamabob, right? Leaving any of those hoses disconnected at either end could also result in vacuum leak.

Can these codes come from failing VANOS piston seals or failing pre-cat O2 sensors? I don't see how the SAP could cause these codes unless there is a vacuum line attached to the SAP and that line is cracked or disconnected. While many E46 have that line, I never could find it on the SAP in my car.

[ryankokesh]

Last time I had one of these codes, I found my F-connector was not inserted into the upper intake boot! If you think oil dipstick is sucking air but you replaced the lower O-ring, could check that the dipstick itself has the two small O-rings at the top under the plastic pull ring.

Could do a smoke test with mechanic or spray the starting fluid/cleaner around the intake manifold while running to look for vacuum leaks.

Lol, I actually also replaced the dipstick itself.

Checked the SAP and all appears to be in very good condition actually. I was really hoping for a split hose...

Might have to go the smoke test route... This is ridiculous!


Sent from my iPhone

[derbo]

Lol, I actually also replaced the dipstick itself.

Checked the SAP and all appears to be in very good condition actually. I was really hoping for a split hose...

Might have to go the smoke test route... This is ridiculous!


Sent from my iPhone

Hope you find the leak.