P0171 System Too Lean (Bank 1)

[mark v]

Yes there are 2 sensors on each side of the manifolds, 4 total for the car. Always replace in pairs.

One is called the upstream and is located near the exhaust manifold and the downstream is located near the converter.

[tbmiller]

Could not agree more. My husband is great at fixing things. It's just knowing what to start with is the problem. He would love for me to get rid of this 2000 Winstar but really don't want a car payment with money as tight as it is.

[s_kuzak@yahoo.com]

P0171 and P0174 codes mean Left side lean and Right side lean.
The Oxy sensors are NEVER the problem. It's the intake doing it.
Go to a Ford dealer and tell the parts guy what your problem is and they have a kit.
It's quite a job and not for the novice. Also, if you're going to do it, remove the deck where the wipers are for better access. Taking my time it took about 4 hours.
Did it last year and it runs perfect and no more codes.

[mark v]

Sounds like BS to me. So your saying O2 Sensors never fail?

Originally Posted by s_kuzak@yahoo.com

P0171 and P0174 codes mean Left side lean and Right side lean.
The Oxy sensors are NEVER the problem. It's the intake doing it.
Go to a Ford dealer and tell the parts guy what your problem is and they have a kit.
It's quite a job and not for the novice. Also, if you're going to do it, remove the deck where the wipers are for better access. Taking my time it took about 4 hours.
Did it last year and it runs perfect and no more codes.

[s_kuzak@yahoo.com]

Originally Posted by mark v

Sounds like BS to me. So your saying O2 Sensors never fail?

That's right, O2 sensors are NEVER the problem for P0171 and P0174 on a Ford 3.8L according to my Service Manager brother-in-law and one of their Senior Mechanics, and they were 100% right. I had the problem off-on for over a year. Fixed it about a year ago and 18,000 miles later, no codes and runs great with 138,000 miles on it.

The primary problem are defective isolator bolt sleeves that oil breaks down over time causing air leaks. The BAD sleeves are BLACK rubber and GOOD sleeves are GREEN silicone. Also, once you take the air intake off you'll also need to replace the port seals and do allot of cleaning.
PS:: This is NOT a job for a novice.

Ford Part# for the 8 Isolator bolts is 3F2Z-9S479-AA
Ford Part# for the 6 Port Seals is XF2Z-9H486-AA

Here's an EXCELLENT web-site that gives you everything including great color pictures.
http://leckemby.net/windstar/windstar01.html

[jonmark1985]

s_kuzak is pretty much right. Oxygen sensor hardly do ever fail. Usually its vacuum leaks, sticking idle air control valves, MAF sensors, or stuck EGR valves that give a lean code.

[microsfoftxpuser21]

wooo theres 4 o2 sensors my friend dont be mistaken upper and lower p0171 lol wrong data i have all data i will post u the help u really need

[microsfoftxpuser21]

wut kind of fuel u using if 87 theres your issue if 89 your good those van use 89 thats why they say use gas line antifreez and dry gas once in a while helps the gas burn better same with fuel injection cleaner each oil change lol