I have a 2002 F150 with V6 and i was told that my oxygen sensors was causing my truck hesitate under acceration when climbing a hill. Need some input on that and also if that is the problem where is the sensor located. Also I checked the codes on by obd and i have code P0174 and that is bank 2 is lean could the oxygen sensor be the cause of that as well

 

The OX sensor only reports the issue that exists and in not usually the problem.
There is usually an air intake leak causing the lean code.
Good luck.

 

Thanks. I have already changed the intake gasket and the rubber grommets that I was told needed to be done first time that code come up and the oxygen sensor was the only other thing I could think of. I don't know if the mass air flow sensor would do that or not. I am at my wits end on this code

 

There are a lot of reasons the code sets.
All related to incorrect intake air to fuel ratio.
Bank 2 is the only side reporting.
Mass Air and areas before the cylinder bank generally affect both banks.
Even crank case seal at the dip stick or a tube rusted through below can affect and cause a code.
Fuel pressure either to high or to low can be a cause of lean or rich codes.
The IMRC hardware can even be a source.
I would use a good scanner to look at the live data for anything out of limits then try to correct that part.
At this point I would clear the code and see what comes back to be sure old history is not causing confusion.
Sorry, but there is not enough to go on at this time but for the causes of the problem.
Good luck.

 

If faulty O2 sensor is the cause, you will also get an O2 sensor code. Without it I wouldn't doubt O2 sensor. I would first do the basic things first like cleaning MAF, plug/wire, fuel filter, air filter, if not done recently.

 

So bank 2 is lean. You need to do more in depth diagnostics. The sensor is not the problem, though a weak sensor could cause one bank to read more lean than the other, but only if a lean condition actually exists.

You will need a scan tool to do these tests. Other methods could be employed than just the tests I'm talking about as well.

Hook up the scan tool and look up the live sensor data. You will need to get RPM, LTFT% on both bank 1 and 2, and STFT% on bank 1 and 2, absolute throttle position, and it wouldn't hurt to add MAF sensor. let the idle stabilize and record the LTFT% readings on both banks, and the STFT%. Increase the RPMS to about 2000 rpm. Record those values again after they stabilize a little. Then increase to 3000 rpm and record the values again.

Now to interpret the data. If the LFTF% is a positive value, it means the computer is detecting a lean condition and is increasing injector pulse width on the affected bank by that percentage. This is usually to compensate for a vacuum leak, faulty sensor of some type, or a plugged injector or low fuel pressure. Negative values mean that a rich condition is being detected, often because of fuel leaks, excessive fuel pressure, faulty sensor readings, faulty injector, etc.

Because you have a lean code, it is obvious that all your LTFT% will likely be positive values. If the LTFT% is significantly higher at idle than the 2000 and 3000 rpm tests, and the 2000 rpm test is higher than the 3000 rpm test, this suggests a vacuum or intake leak because the leak comprises a greater percentage of the air that makes it to the engine. So the computer has to add more fuel at idle to overcome the vacuum leak, a leak that becomes almost insignificant when the throttle is opened more. The severity of the leak can be indicated by the percentages. Higher percentages indicate a larger leak.

The leak is likely located in a position that affects bank 2 more than bank 1, or the O2 sensor on bank 2 is slightly weak, which the computer will interpret as a leaner condition. My guess though is that according to the above test, both banks are lean, but only one is setting a code, the one that is affected more strongly. Most the vacuum lines will affect both banks almost equally, same with the PCV lines. Don't rule those locations out completely, but they are not top suspects. More likely locations that would affect bank 2 more include the IMRC runners (each is sealed with an o-ring which can leak over time), the lower intake runners, or a plugged injector on the affected bank. A plugged injector will likely be accompanied with a misfire, though you might not have a misfire code.

Your O2 sensors are likely overdue for replacement. Not a bad idea to replace both upstream sensors, but as others have said, that is very unlikely to clear up your lean code.

 

Only time I had a P0174 it turned out to be an exhaust leak where the manifold bolts to the pipe, fresh air being sucked in.