2002 focus engine light on, code po171, whats that?

P0301 is a engine misfire code for #1 cylinder , spark plug or plug wire problem or a bad fuel injector . Po171 system lean code . Lack of fuel , clogged fuel filter , vacuum leak . https://www.obd-codes.com/p0171 There are ways to test O2sensors before replacing . Your best bet take your vehicle to a qualified repair shop .

First step is to look up Jeep trouble code PO171
This is the link I found:
http://engine-codes.com/p0171_jeep.html

I don't know about the airbag or abs lights. My old AMC concord used to light up all sorts of odd ball combinations of lights to signal stuff not related. You could look under your seat to see if any wire harnesses have come unplugged by stowing things under the seat but if nothing is hanging down obviously I would focus on the code PO171 first. Which as you can see has a lot of possible fuel and air type problems. It points you in the general direction. It is the actual behavior and performance of the engine that is your main concern. How is it running and is there any other symptoms or power loss you can feel and when? Have you done your regular maintenance and replaced your air filter or any recommended fuel filter changes from the owner's manual? If that stuff is done often the appropriate spray cleaner from the auto parts store can get things back without any repair at all. I sprayed one sensors harness with electronic cleaner and my code went away because oil and dirt from my smoky engine was blocking the signals.

Most likely a Oxygen sensor.

with the engine cold spray the intake manifold near the gasket with the carb cleaner see if the idle changes if it does replace the gasket

Google the Codes
OBD PO171 etc & print a code chart
They are Oxygen Sensors-lean on both banks
They should have been changed at 100,000
miles on all your vehicles.

www.engine-light-help.com/generic-engine-check-light-codes.html

It means your O2 sensor has detected a lean condition, solutions to the problem can be found at this link http://www.obd-codes.com/p0171

check your cruise control unit first

PO171 means that the MAF (MASS AIRFLOW SENSOR )sensor is dirty or deffective . Or that there is a leak in the vacume hose leading to the MAF sensor.Try cleaning the MAF sensor with brake cleaner .Be careful not to damage it.Check your Air filter also. Make sure it is clean. the reason the MAF sensor gets dirty is because of the filter. Also look for any leaks in the hose or hoses connected to it.It is located near the top of the air filter...little black box with wires coming out toward the front of the car.

i think its the oxygen sensor (pre cat) in exhaust