Fuel trim code - 1996 Nissan Altima

What code P0000 ?

Fuel Trim Index
Fuel Trim
%
0% +/- 10%

P0300 is a random miss fire , a vacuum leak can cause this as well as low fuel pressure ! weak fuel pump , clogged fuel filter !
DTC P0171: Fuel Trim System Lean Bank 1
DTC P0174: Fuel Trim System Lean Bank 2 These two codes are saying the PCM - engine computer is see a lean condition .
DTC P0191: Fuel Rail Pressure (FRP) Sensor Performance
Circuit/System Description
The fuel pressure sensor is located on the fuel line. The fuel pressure sensor monitors the fuel pressure in the fuel line. The fuel pump flow control module (FPCM) monitors the voltage signal from the fuel pressure sensor.

You don't say what make , model an year vehicle ! These are for GM vehicles , yours could mean something else . Except the first three , those are genaric codes , same for all makes ! So can't say what this codes are P2097, and P2099 ! Can't mean this P2097 - Post Catalyst Fuel Trim System Too Rich Bank 1
P2099 - Post Catalyst Fuel Trim System Too Rich Bank 2

Fuel trim out of range is an indication of too much fuel (leaky injector) or too little fuel (vacuum leak) with out seeing the specific code its difficult to tell you where to look. Post the code and engine size, 3.5 ltr, 2.5 ltr...etc.... I can give you specifics.

Diagnostic Test Code (DTC) P0171 is defined by SAE J2012 as "System Too Lean Bank 1".
This is what is known as a fuel trim code. Something is causing the fuel trim on bank 1 of your engine to reach a predetermined maximum set point. This can be caused by many things including vacuum leaks, malfunctioning injectors, a fauly mass airflow sensor, or even a catalytic converter that is clogged up.

If there are no fuel trim problems on the opposite bank, then there is a problem that affects only one bank. It is necessary to access the fuel trim data to correctly identify the problem. You may have fuel trim problems on the opposite bank that have not yet set a code. If the fuel trim data proves that there is no problem on the opposite bank, then this rules out several possiblities like the mass airflow sensor, as it will affect BOTH banks, not just one.

To put it simply: Proper diagnosis required.

You have big problems here, I suggest you go to the provided links and read about these fault codes and then hire a good technician.
Ford P0171 P0174 Lean Codes

P0172 OBD II Trouble Code System Too Rich Bank 1 YourMechanic Advice

https://www.obd-codes.com/p0175


P0304 OBD II Trouble Code Cylinder 4 Misfire Detected YourMechanic Advice

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

2-3-2* Fuel trim (lambda control) too lean or too rich at idle }If too rich: high fuel press., leaking injector } various driving problems Fuel trim (lambda control) too lean at idle Oxygen sensor

Check for vacuum leaks around the intake. This is the most common cause for these codes.

I'm not quite sure about the code in Hyundai's case but it definitely relates to fuel trim...

I could try to hash down the explanation for Short term fuel trim and Long term fuel trim in this post but I think a visit to
http://www.wellsmfgcorp.com/pdf/counterp_v6_i4_2002.pdf
would be more thorough and appropriate.

Basically, a high value of long term fuel trim indicates that your engine has had and will have to continue to inject a lot more or a lot less fuel to attain the correct air/fuel ratio for a proper burn, which mainly indicates a malfunction somewhere (could be lots of things)