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2007 Taurus Lean Code Issue

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BigDogg
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Vehicle: 2007 Ford Taurus SE

2007 Taurus Lean Code Issue

Post by BigDogg » Thu Jul 20, 2017 12:24 pm

My 2007 Ford Taurus SE has these mods to the drivetrain:
Stroker Kit (3.3L Vulcan)
K&N Air Filter
Insynerator Turbo Tube muffler (To replace the stock resonator)
Flowmaster Catalytic Converter (To replace the factory third cat)
3" Exhaust from cat to rear w/2.5" Dual Tailpipes
Factory Muffler Deleted

The check engine light came on and after having a reader scan it said it had a lean condition on the left bank side. Since the original pre cats had over 200,000+ miles on them I had them replaced with front and back O2 sensors. Had the fuel filter replaced and checked for vacuum leaks and replaced the PCV valves. No luck. Since the car runs great and has no issues I kinda lived with it for the year til a friend told me that the MAF sensor could be the problem. I heard that having a reusable air filter can cause the issue with the check engine light coming on due to the MAF sensor getting dirty from the oil used on the filter. What do you guys think? Could it be that all along? Any input would help a lot. If that is the case will a simple cleaning of it would fix the problem? Thanks again for the help.


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Re: 2007 Taurus Lean Code Issue

Post by Webmaster » Thu Jul 20, 2017 7:30 pm

What is the exact code? P0171 or P0174 I assume?

https://www.obd-codes.com/p0174 - same for either bank.

The problem with modifying a car is the car operates under different parameters than it was meant for. Oiled air filters have been known to be problematic to the MAF. The more you modify the more the likelihood of seeing faults because the tolerances for things in the PCM's strategy are designed around a stock vehicle.

In fact, simply changing the location of the O2 sensor in the exhaust stream can modify things such that the sensor reading is out of the normal parameters for the PCM. Moving the sensor forward or back a bit can make a difference in the engine's performance.
BigDogg wrote:Since the original pre cats had over 200,000+ miles on them I had them replaced with front and back O2 sensors.
That doesn't make sense. You replaced cats with O2 sensors, huh??
BigDogg wrote:Had the fuel filter replaced and checked for vacuum leaks
Who checked for vacuum leaks? Did you/he also check for exhaust leaks? And how did you/he check, using a smoke machine?
BigDogg wrote: til a friend told me that the MAF sensor could be the problem
Is he a mechanic?
BigDogg wrote:I heard that having a reusable air filter can cause the issue with the check engine light coming on due to the MAF sensor getting dirty from the oil used on the filter.
Totally true. I've run K&N filters in the past but you couldn't pay me to do that ever again.
2000 Ford Taurus SEL (excellent car, sold to a friend)
1992 Mercury Sable GS (good car except for the tranny, sold)
Current: 03 F150 King Ranch SuperCrew
Other Fords owned: 02 F150 SuperCrew 4x4, 11 F150 EcoBoost, 07 Ranger, 01 F150 XLT, 98 F150 XLT, 96 Thunderbird LX, 95 Escort GT, 86 Mustang LX, 82 Mustang

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BigDogg
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Vehicle: 2007 Ford Taurus SE

Re: 2007 Taurus Lean Code Issue

Post by BigDogg » Thu Jul 20, 2017 10:34 pm

You might be right about the mods. I stroked a Vulcan out of a Winstar and swapped in the engine with help of a friend. Runs good but that Check Engine light is driving me nuts. The two pre cats and all 4 O2 sensors was replaced with factory placement units I bought from O'Reilly's by a ASE approved mechanic at his shop. He also checked for vacuum and exhaust leaks along with replacing the PCV valve since they all was original on the car. It runs great. Had it dyno tested and it Makes 203 to the wheels and my last road trip which was 2200+ miles round trip I averaged 27 mpg. My issue is it thows that code and I can't figure out why. It did start a month after I installed my K&N filter and my friend told me about his MAF sensor issues after he installed his. I am planning on cleaning mine tomorrow and seeing how it turn out.

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BigDogg
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Re: 2007 Taurus Lean Code Issue

Post by BigDogg » Thu Jul 20, 2017 10:43 pm

I forgot to mention that at first it threw a PO171 before I had it looked at. When I had everything replaced and checked for vacuum leaks the code went away just for a PO174 code to pop up a month later.

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BigDogg
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Re: 2007 Taurus Lean Code Issue

Post by BigDogg » Fri Jul 21, 2017 2:58 pm

Update. I took the MAF sensor off and sprayed it with MAF cleaner and let it dry before installing it and the PO174 went away and now it idles better so it was dirty. Probably from the K&N filter oil. It tripped the PO171 code again after 15 minutes of driving but still runs great. Got a reply from the company that made the stroker kit and I was told that I will need a reflash tune of the computer in order for the engine to run a peak efficiency and to keep it from throwing codes. They also told me the engine should also put out at least an extra 20+ hp after i get it done. I will have to wait on that. It cost a little $$$.

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Re: 2007 Taurus Lean Code Issue

Post by Webmaster » Fri Jul 21, 2017 4:30 pm

Yeah if the PCM doesn't know about the changes it won't be running optimally. Strange that the lean code is jumping from bank to bank.
2000 Ford Taurus SEL (excellent car, sold to a friend)
1992 Mercury Sable GS (good car except for the tranny, sold)
Current: 03 F150 King Ranch SuperCrew
Other Fords owned: 02 F150 SuperCrew 4x4, 11 F150 EcoBoost, 07 Ranger, 01 F150 XLT, 98 F150 XLT, 96 Thunderbird LX, 95 Escort GT, 86 Mustang LX, 82 Mustang

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BigDogg
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Posts: 82
Joined: Thu Jun 26, 2014 8:26 am
Vehicle: 2007 Ford Taurus SE

Re: 2007 Taurus Lean Code Issue

Post by BigDogg » Sat Jul 22, 2017 1:37 am

It is weird alright. Makes no sense but it doesn't have any issues. Doesn't run rich or has any detonation. It is almost if not faster acceleration wise as my friends '96 SHO. I will get the tune in a month and will keep you updated on what happens.

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BigDogg
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Posts: 82
Joined: Thu Jun 26, 2014 8:26 am
Vehicle: 2007 Ford Taurus SE

Re: 2007 Taurus Lean Code Issue

Post by BigDogg » Sun Jul 23, 2017 7:09 pm

Update. A cousin let me use his ecu programmer on the Taurus and it seemed to fix the problem. I programmed in the mods I did to the car and since yesterday morning no codes came up. MPG went up by 2 miles too on my 420 mile round trip from San Antonio to Houston.

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Re: 2007 Taurus Lean Code Issue

Post by Webmaster » Tue Jul 25, 2017 3:41 pm

I'm not sure what tuner you used but be aware that some tuners become locked when you apply a tune. In other words the tuner can't be used on anything else until that vehicle is put back to stock. I guess we'll say case closed on this one.
2000 Ford Taurus SEL (excellent car, sold to a friend)
1992 Mercury Sable GS (good car except for the tranny, sold)
Current: 03 F150 King Ranch SuperCrew
Other Fords owned: 02 F150 SuperCrew 4x4, 11 F150 EcoBoost, 07 Ranger, 01 F150 XLT, 98 F150 XLT, 96 Thunderbird LX, 95 Escort GT, 86 Mustang LX, 82 Mustang

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