I'm trying to track down a p0171/p0174 that has so far passed every single EGR, evap, and vacuum test I can think to run...so maybe it's a bad MAF? What do you NA guys get for idle MAF readings? Would prefer gm/s or kg/hr in case your MAF is different.
MAF at idle
- Thread starter po-po 5.0
- Start date
clean the maf with some maf cleaner and go from there
Done that 3x
Replaced Intake gaskets
Smoked the intake
Smoked evap
Replaced filler neck gasket
Vacuum and pressure tested EGR
Replaced an oxygen sensor
Replaced Injector o-rings
I've even plugged every vacuum accessory and driven around.
Hell, I went so far as to fill the intake with water to make sure a casting plug wasn't leaking.
Trust me, when I said I've tried things...I meant it.
Replaced Intake gaskets
Smoked the intake
Smoked evap
Replaced filler neck gasket
Vacuum and pressure tested EGR
Replaced an oxygen sensor
Replaced Injector o-rings
I've even plugged every vacuum accessory and driven around.
Hell, I went so far as to fill the intake with water to make sure a casting plug wasn't leaking.
Trust me, when I said I've tried things...I meant it.
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Give a Fuel filter a try
Replaced fuel filter as well.trims are only maxed at idle so I didn't think that would help. It didn't.
Infamous P0171 & P0174 codes - E46Fanatics
I knew I'd seen those codes somewhere before...wife has a bmw..I've got the audi..
Maybe this will help...some had to replace the fuel pump (pg 2)
swap COPS and see if problem shows in diferent cylinders??
http://forum.e46fanatics.com/showthread.php?t=699464
WAG: run some kreen or something through it??
I knew I'd seen those codes somewhere before...wife has a bmw..I've got the audi..
Maybe this will help...some had to replace the fuel pump (pg 2)
swap COPS and see if problem shows in diferent cylinders??
http://forum.e46fanatics.com/showthread.php?t=699464
WAG: run some kreen or something through it??
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O2 sensor or intake gasket
And you probably already have this link
Part 1 -Troubleshooting P0171 and P0174 (Ford 4.6L, 5.4L)
I'll go away now..
And you probably already have this link
Part 1 -Troubleshooting P0171 and P0174 (Ford 4.6L, 5.4L)
I'll go away now..
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Already replaced o2 sensor and intake gasket
Can someone just give me their MAF reading at idle!?
Can someone just give me their MAF reading at idle!?
Part 1 -How to Test the Ford MAF P0102, P0103 (4.2L, 4.6L, 5.4L).
Part 1 -Ford MAF Sensor Test (P0102, P0103, P1100, P1101)
my Haynes manual says 0.2-1.5V at idle between MAF SIG and Ground.
and shouldn't fluctuate or spike when revved..but will climb a bit.
I have no info for a scan tool reading...but that the manual says the MAF should read ~2v at 60 MPH..(presumable read with a scan tool while driving.)
Part 1 -Ford MAF Sensor Test (P0102, P0103, P1100, P1101)
my Haynes manual says 0.2-1.5V at idle between MAF SIG and Ground.
and shouldn't fluctuate or spike when revved..but will climb a bit.
I have no info for a scan tool reading...but that the manual says the MAF should read ~2v at 60 MPH..(presumable read with a scan tool while driving.)
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MAF reads ~.65V at idle. I'm completely at a loss for what might be causing this.
The only "old" intake gasket is the plenum gasket, but I've hosed the entire area with carb cleaner and propane without an idle change.
Could a leaking header gasket cause this? I don't hear an exhaust leak at all.
The only "old" intake gasket is the plenum gasket, but I've hosed the entire area with carb cleaner and propane without an idle change.
Could a leaking header gasket cause this? I don't hear an exhaust leak at all.
http://troubleshootmyvehicle.com/fo...ubleshooting-p0171-and-p0174?showall=&start=2
copied from this link....
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Most Common Causes of P0171, P0174 DTC's
Although this is not the most complete list of causes... here are the ones that I've encountered on a regular basis:
CAUSE 1: PCV Tube's rubber elbow (where it connects to the Intake Manifold) is torn open and causing a major Vacuum Leak.
CAUSE 2: Intake Manifold Gaskets that are leaking Vacuum.
CAUSE 3: Fuel Pump that's going BAD, but hasn't completely fried yet.
CAUSE 4: A dirty (contaminated) MAF Sensor.
CAUSE 5: An exhaust leak right before the pre-Catalytic Converter Oxygen Sensors.
CAUSE 6: BAD pre-Catalytic Converter Oxygen Sensor.
Remember... the most important thing to consider (or keep in mind) when you're troubleshooting a P0171 or a P0174 trouble code is that whatever is causing it... is making the PCM think that too much unmetered air is entering the engine.
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so what you said about an exhaust leak..or fuel pump..I'd test the fuel pump.
At least I'll give you a bump ttt
copied from this link....
*************************
Most Common Causes of P0171, P0174 DTC's
Although this is not the most complete list of causes... here are the ones that I've encountered on a regular basis:
CAUSE 1: PCV Tube's rubber elbow (where it connects to the Intake Manifold) is torn open and causing a major Vacuum Leak.
CAUSE 2: Intake Manifold Gaskets that are leaking Vacuum.
CAUSE 3: Fuel Pump that's going BAD, but hasn't completely fried yet.
CAUSE 4: A dirty (contaminated) MAF Sensor.
CAUSE 5: An exhaust leak right before the pre-Catalytic Converter Oxygen Sensors.
CAUSE 6: BAD pre-Catalytic Converter Oxygen Sensor.
Remember... the most important thing to consider (or keep in mind) when you're troubleshooting a P0171 or a P0174 trouble code is that whatever is causing it... is making the PCM think that too much unmetered air is entering the engine.
******************************
so what you said about an exhaust leak..or fuel pump..I'd test the fuel pump.
At least I'll give you a bump ttt
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Lean fuel trims only appear at idle. If it was the pump, it'd get worse with increased fuel demand.
popo i am in the same place as you....I have a C/L maf and had a diablo chip when i got car. I had the diablo removed and a SCT tune put in though the X3. had the codes since then, problem is that when i put the diablo back in and removed the SCT tune i still had them..... GGGRRrrrr. I just got a factory MAF off a guy on here and i hope thats it. I ve done all the things you have also, and I to am at a loss. through the X3 my fuel pump duty cycle is right and all my numbers are right at ide, just under load it kicks the codes. I hope you figure it out becuz i will copy what you do and try it on mine.
Make sure to have your tune updated with a stock MAF transfer curve vs. the one for the C&L.
By chance are you also throwing a code for slow O2 response?
Nope. Just the p0171 and p0174. Watching fuel trims, you can see the o2 sensors changing like they're supposed to. They still change at idle, they just don't ever switch lean.
NO ONE has a handheld they can datalog their MAF at idle, and give me a reading in kg/hr, Gm/S, or lb/min?!
I have datalogs, but I'm not running a stock MAF or a stock housing. So I imagine that would change things.
The reason I was asking is because I noticed you're running shorty headers. Which shouldn't make a difference, but before I turned up the duty cycle on my O2 heaters I would get rich and lean codes. Granted I have mid lengths, but that's what I was thinking of.
The reason I was asking is because I noticed you're running shorty headers. Which shouldn't make a difference, but before I turned up the duty cycle on my O2 heaters I would get rich and lean codes. Granted I have mid lengths, but that's what I was thinking of.
Your MAFV would be different, but the air mass should be the same.
Assuming you have stock heads and cams.
03 heads, Ford GT cams, big bore stroker. My air requirements are probably a little different.
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03 heads, Ford GT cams, big bore stroker. My air requirements are probably a little different.
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Just a pinch...
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