2000 Taurus P0174 code only HELP

[abond0017]

Last week my check engine light came on and I had the code read at Autozone. P0174 (Bank 2 running lean) is what was pulled. I looked under the hood around bank 2 and noticed that the wires to the 1st O2 sensor for bank 2 were melted from resting against the metal. Naturally we replaced it thinking that was what it had to causing the problem. Not so, CEL came back on. Next we checked the hoses for a leak, found nothing. Cleaned the MAF sensor, light still on. The auto shop I used to take my car to has changed ownership and I have gotten screwed so many times from dishonest shops, I am afraid to walk into one with this problem. They could say it is all kinds of things and take my money. I need help.
I have looked on many forums for suggestions, but everytime I see one for P0174 they also are having the P0171 code. I only have the P0174. I dont want to waste time by checking things that throw both codes. I need suggestions for only things that would cause a lean condition on Bank 2.
The engine makes a slight rattle noise when idling, however I don't hear any rattling when driving (might just not be loud enough). My gas mileage is about 16 mpg now. My exhaust smells very toxic, but not like rotten eggs.
Don't know when the last tune up was cause we bought it a less than a year ago. Oh and it has 130,000 miles on it. The CEL came on right after I floored it and pushed the engine to 95 mph in a hurry to get somewhere. Hope this stuff helps you help me.
Thanks in advance.

[abond0017]

I just took another look at the MAF and the little wire in the sensor has a grey spot in the middle of it. Hard to describe, almost like it burned but stayed the same grey color. Maybe something? Maybe nothing?
Wouldnt the MAF sensor affect both banks, though?

[shorod]

Yep, the MAF would likely affect both banks of cylinders, but it would be worth cleaning anyway. If it really is dirty, then your fuel economy may be low because of it, even if it doesn't fix the code issue.

-Rod

[abond0017]

I already cleaned the MAF. I just need to know what could be causing only the P0174 code. I dont have both P0171 & P0174 so I am having trouble finding any resources that have info. only on P0174.

[shorod]

The steps to troubleshoot a P0174 are the same as for a P0171, except you are likely looking for something tied to a lean condition on only bank 2. Per the factory service manual, the causes for a P0174 are:

• Fuel system
• Excessive fuel pressure.
• Leaking/contaminated fuel injectors.
• Leaking fuel pressure regulator.
• Low fuel pressure or running out of fuel.
• Vapor recovery system.
• Induction system:
  • Air leaks after the MAF.
  • Vacuum Leaks.
  • PCV system.
  • Improperly seated engine oil dipstick.
• EGR system:
  • Leaking gasket.
  • Stuck EGR valve.
  • Leaking diaphragm or EVR.
• Base Engine:
  • Oil overfill.
  • Cam timing.
  • Cylinder compression.
  • Exhaust leaks before or near the HO2Ss

Maybe a good place to start would be with a bottle of fuel injector cleaner in the fuel tank and a 50 mile run on the highway. Also, if you have access to a scan tool with a datastream mode, monitor the Bank 2, Sensor 1 oxygen sensor for appropriate response time and cross counts, as well as heater current within specification.

If you'd like a copy of the troubleshooting procedure for code P0174, send me a private message with your request and an e-mail address for you that can accept PDF attachments.

-Rod

[Huney1]

My 03 Vulcan threw a code bank1 sensor1 rich or lean, can't remember which so I cleaned the MAF and did no good, changed the O2 sensor and the Cel went away. O2 sensor abot $40. and rent the tool to change it, takes about 15 minutes. Good luck. Oh, check the PCV and the gromet it sits in. They get old and leak. New Gromet and valve about six or eight bucks.

[hughw]

Check the pcv valve and little elbow hose attached.
The elbow hose tends to disentergrate because of
the heat ..That will give a bank 2 code
...Hard to find a replacement for the hose, I made one
form another larger piece of hose ...The bend is so tight
you have to be careful that it doesn't close at the bend.

[Birney]

Hughw is right. The elbow that attaches the pcv valve from the right valve cover to the intake plenum does disentegrate with age. It is hard to detect the vacuum leak it causes because it will only leak when full manifold vacuum is applied to the weakend elbow (engine running). Code P0174 is common when this elbow is leaking.
You don't have to McGuyver the part however as Hugh suggests. You can go down to the Ford dealer and buy one. They are not cheap, about $27.00 but it's cheaper than O2 sensors, Maf sensors, egr valves etc. So check this elbow out by looking at it from the inside and if it is even slightly cracked replace it because if it's not the cause of your code right now, it will be soon!

[laybackman]

Just went throught this last week with an '00 taurus 3.0 4V Check the EGR hose at the EGR valve. The underside goes bad sucks air and it will cause lean condition on both banks!
You will need to get an upper intake gasket kit. It has two EGR gaskets six upper a six lower intake gaskets and injector O rings. The upper intake has to be shoved aside to ge at the lower end of the EGR hose.