P1165 code in my 2001 hyundai santa fe?

code p0170 refers to two problems
fuel trim bank 1 --malfunction
heated oxygen sensor(HO2S) 3 bank1 --circuit malfunction
for the first error==causes-- intake leak --AIR system---fuel pressure /pump---injectors--EVAP canister purge valve---HO2S
for the second one ===causes=--wiring--HO2S---ECM
The explanation of fuel trim is long winded and you may get some typo errors but I think that you will get the idea
short and long term fuel trim refers to the strategy used to reduce exhaust emissions after a basic computation of injector period, using engine load as a major parameter
both front and rear oxygen sensors signals are used to fine tune the air/fuel mixture by increasing or decreasing the injection period =/- 25% above or below the basic level
any fault requiring a correction beyond this level will result in a fault code being logged ( in this case p0170)
the fuel trim will oscillate the injection period =/- 5% above or below the mean level level A
manufacturing and in-service tolerances of load sensors (MAP,MAF, VAF) and injectors in particular and faults such as intake leaks( vacuum hoses from vent controls and transmission) will affect the air/fuel mixture and cause the trim to compensate
an air intake leak for instance would increase the injection period increasing for example to 115-125%. this level will also oscillate +/- as before level B
this new short term fuel trim level will be stored in the ECM if it is established as a new basic mixture level
It will become a long term fuel trim correction and results in the correct mixture level immediately after starting, even when the HO2S has had sufficient time to heat up
Now having some idea of what trim is, you will see the necessity of repairing any problem sensors ,air leaks ,vacuum leaks
You will also probably understand the reason of why an engine after running short runs ( city driving) feels that it gets more power and better economy after 1/2 hour on the open highway
The ECM resets the trim to the new load power settings and that becomes the new trim

You could have leaking fuel injectors an fouled spark plugs causing the misfire ! I would pull the spark plugs out an see if wet with fuel . Could also have a leaking fuel pressure regulator ! How To Fix P0300 random misfire codes in your car

O2 Sensor Signal Fixed Rich http://youtu.be/H6lY42u19VM
The front oxygen sensor sends signals on exhaust gas oxygen content to the PCM to control a 14.7:1 air/fuel ratio under normal driving conditions. The PCM can make fuel corrections from a nominal 128 (0% correction) short/long term fuel trim value to a maximum window of 101-147 (-21 to +15 percent). If the PCM determines a rich condition exists, 02 voltage above 450 mV, it will decrease injector pulse width, reducing fuel, to maintain a 14.7:1 air/fuel ratio. The short term fuel trim value will be between 101-128 indicating a rich condition. If the PCM determines a lean condition exists, 02 voltage below 450 mV, it will increase injector pulse width, adding fuel, maintaining a correct air/fuel mixture. The short term fuel trim value will be between 128-147 indicating a lean condition. When certain conditions have been met to begin learning fuel control (ECT, closed loop, etc.) the PCM will use the short term fuel trim cell to update 1 of the 4 long term cells (idle, decel, cruise, accel) being used. During every drive cycle, or trip, the PCM will use and update the idle and cruise long term cells and will keep track of how long the control system is operating in these cells. After approximately 2 minutes of being in each of these cells, the fuel control system will enable EVAP purge and the purge long term cells will be used. Refer to EVAP Canister Purge for information on purge long term fuel cells. If the average of the idle and cruise fuel cells is 147 and the short term fuel trim cell is currently over 128, a lean fuel system DTC will set. This test is performed before the purge cells are used.
http://youtu.be/QDNrFcARMd0

Lean condition bank 1 refers to the computers interpretation of information delivered by the o2 sensor for bank 1. Possible causes are many. First look at the sensor readings. You should see a fluctuation of voltage readings. If the sensor is not fluctuating it should set another code with it. The readings should be .05 v to about .455 volts normally. If the readings are lean then look at the fuel trims. They will likely be nowhere near 0. When the engine is right, the trims may go positive 3 to negative 3. If your short term fuel trim is say +18 and the long term fuel trim is say +20 at idle then try runnung the engine at a steady 1600 rpm and wait a minute till the readings level out. If they approach 0 then look for a vacuum leak. Let the engine idle and use choke cleaner spray to find the leak. Spray suspect areas and watch for changes in fuel trims.

Check the gap on your plugs, also check to make sure you don't have bad spark plug wires. At night start your car and look at the spark plugs IF you see any sparks that look like lightning then you have a bad plug, or wire.

Trouble Code: P0171

Fuel Trim Too Lean

Possible Causes:


The current cell can be observed using a scan tool.The system will go lean if an injector is not providing enough fuel.A lean condition could be present during high fuel demand due to a fuel pump not pumping enough fuel, plugged fuel filter or a restricted fuel line.Insufficient fuel in the tank or low fuel pressure may cause this DTC to set. Refer to Fuel System Diagnosis .Review the Failure Records with a scan tool. If an intermittent condition is suspected, refer to Intermittent Conditions .

DTC P2187: Fuel Trim System Lean at Idle

Fuel Trim Description
The Engine Control Module (ECM) controls the air/fuel metering system in order to provide the best possible combination of driveability, fuel economy and emission control. Fuel delivery is controlled differently during Open and Closed Loop. During Open Loop, the ECM determines fuel delivery based on sensor signals without Heated Oxygen Sensor (HO2S) input. During Closed Loop, the HO2S inputs are added and used by the ECM to calculate short and long term fuel trim fuel delivery adjustments. If the HO2S indicate a lean condition, fuel trim values will be above 0%. If the Heated Oxygen Sensors (HO2S) indicate a rich condition, fuel trim values will be below 0%. Short term fuel trim values change rapidly in response to the HO2S signals. Long term fuel trim makes coarse adjustments in order to maintain an air/fuel ratio of 14.7 : 1.

This code can only set when the engine control is in Closed Loop. The engine must be fully warmed up.

This must be diagnosed using a scan tool that can read engine data in order to determine the actual cause of the problem. It can be caused by the following things:

> Vacuum leaks
> Malfunctioning, dirty, or skewed Mass Airflow Sensor (MAF)
> Malfunctioning or skewed Manifold Absolute Pressure Sensor (MAP)
> Dirty or sticking injectors
> Malfunctioning or improperly programmed Powertrain Control Module (PCM)

DTC P0171 is set when fuel trim is driven rich beyond a certain value. Possible causes are:
1. Exhaust system leak.
2. Improper fuel pressure.
3. Fuel injector restricted.
4. Defective heated oxygen sensor No. 1.
5. Defective Manifold Absolute Pressure (MAP) sensor.
6. Defective Engine Coolant Temperature (ECT) sensor.
When the air fuel ratio feedback is stable after the engine is at operating temperature and the fuel trim has reached its limit of correction to the rich side. (2 trip logic).
Feedback from the HO 2 sensor influences short-term fuel trim and short-term fuel trim influences long trim fuel trim. Short-term values are temporary and not stored when the ignition key is turned off. Long-term values are stored in memory because they are part of the basic injection duration. Long term values affect injection duration in closed and open loop because they are used to calculate basic injection duration. It is important to remember that the actual fuel trim will be the opposite of the DTC. A system too lean, DTC P0171 will mean the ECM is making a + or rich correction.
read (and let me know)above data and Freeze Frame by using (example, generic) Scan Tool on # mode 2, etc.
Slowly accelerate the engine in the increments shown and record voltage,
grams/sec of MAF and SFT, LFT, Injection Pulse, Fuel Pressure, etc.
HTH,
Vehicle have MAF Sensor?

Because you got a misfire on cylinder #1 PO301
A misfire on cylinder #2 PO302
Misfires first 1000 rev PO316
O2 Codes PO 174
Etc,Etc


The LTT, is the result of not learning (yet-thus long term)
what isn't working correctly---Your Engine

Replace bad Coil--which ever is missing
Do not go by the codes,alone ,TEST

It measures the oxygen in the exhaust system, for instance, if the fuel is to rich it sends values to the computer and the computer will adjust the fuel and timing to bring it back into perimeters

Here is some general information to get you started...
(I am quoting directly from several PDF sources, Googled).

STFT B1 = Short Term Fuel Trim Bank 1. This is the fuel correction percentage being used by the closed loop fuel strategy for Bank 1 (if a V style engine or for all cylinders if an inline engine). If the fuel system is in open loop, this number will be reported as 0%

Fuel trim refers to the feedback compensation value compared against the basic injection time. Fuel trim includes short–term fuel trim and long–term fuel trim.

Short–term fuel trim is the short–term fuel compensation used to maintain the air–fuel ratio at its ideal theoretical value. The signal from the heated oxygen sensor indicates whether the air–fuel ratio is RICH or LEAN compared to the ideal theoretical value, triggering a reduction in fuel volume if the air–fuel ratio is rich, and an increase in fuel volume if it is lean.

Long–term fuel trim is overall fuel compensation carried out long–term to compensate for continual deviation of the short–term fuel trim form the central value due to individual engine differences, wear over time and changes in the usage environment.

If both the short–term fuel trim and long–term fuel trim are LEAN or RICH beyond a certain value, it is detected as a malfunction and the check engine warning (CHK ENG) lights up.

If the total of the short–term fuel trim value and long–term fuel trim value is within ± 25 %, the system is functioning normally.