I have the following codes coming up for my 2003 jeep liberty. P1282, p0171, p0174, p0306

SOURCE: check engine light codes, p0171,

this fords have very comun problems with maf sensors geting contaminated, if you have not or can hear any vacium leaks, the problem is goin to be a conataminated mas air flow snsor (maf)
allow the engine to cold down for at least 15minutes and the remove the air filter hosing and inside has to have a sensor, clean the two liitle resistors inside with brake or carburetor cleaner, allow it to dry and reinstall it.
if this inf help please mark it as fixya ranking after you try what i said

SOURCE: 98 E-250 Rough Idle; codes p0156,p1131,p1151,p0301,p0171,p0174+

po301 thru po306 all misfire codes cylinder 1-6 remove plugs and replace them..... set the plug gap first
i suggest u replace the wires also if they never been replaced all these misfire codes can set the others and one is for the oxygen sensor ( 02s or HO2S) CIRCUT MALFUNCTION do u know how to check wireing systems
do the tune up plugs (set gap) .052-.056 change the fuel filter also. clear the codes hows it run
this info is for 98 E-250 4.2Litre
what engine do u have 4.2L or 4.6L i know it is a v-6 by the codes

SOURCE: p0171 and p0174 codes

P0171 System too Lean (Bank 1)
P0174 System too Lean (Bank 2)

If a car has a check engine light on and has P0171 and P0174 codes stored, the most likely cause is a vacuum leak. These codes are set by the car’s computer when it sees too much oxygen in the exhaust. Excessive oxygen readings in the exhaust will set lean codes. This does not mean that the oxygen sensors are defective. It is a common mistake for people to replace oxygen sensors when lean codes are present. Just because the code is related to oxygen sensor readings, it doesn’t mean that the oxygen sensors are bad. If both of these codes are stored this means that both banks of the engine have excessive oxygen in the exhaust. If the oxygen sensors are replaced it’s most likely that the same codes will reappear. It is very uncommon for two oxygen sensors to fail at the same time.

Therefore the most likely cause of P0171 and P0174 codes is a vacuum leak. The source of a vacuum leak can be one of many things. The most common cause of a vacuum leak is a leaky hose. Vacuum hoses over time can become dry and brittle. The rubber deteriorates and can leak causing a vacuum loss. Many times a leaky vacuum hose can be found by listening for a hissing sound. A large vacuum leak can even make the car run rough at idle. In some cases it will not idle without feathering the gas pedal.

SOURCE: codes p171 and p0174 on a chevy truck?

Subject: 97-05 Vehicles with 4.8 5.3 5.7 and 6.0 Gen III V8 Engines and Misfires on One Bank - kw CEL diagnostics driveability DTC P0171 P0172 P0174 P0175 P0300 P0301 P0302 P0303 P0304 P0305 P0306 P0307 P0308 #PIP3056 - (07/12/2004)

Models: (00-05 Cadillac Escalade - C6 and K6) and (02-05 Chevrolet Avalanche - C1, C2 K1 and K2) and (99-05 Chevrolet Silverado - C1, C2 K1 and K2) and (00-05 Chevrolet Suburban - C1, C2, K1 and K2) and (00-05 Chevrolet Tahoe - C1 and K1) and (99-05 GMC Sierra C1, C2 K1 and K2) and (00-05 GMC Yukon - C1, C2, K1 and K2) and (03-05 Chevrolet Express G1, G2, G3, H1, H2 ) and (03-05 GMC Savana G1, G2, G3, H1, H2 ) and (04-05 Buick Rainier S1, T1 ) and (03-05 Chevrolet Trail Blazer EXT S1, T1 ) and (03-05 GMC Envoy XL XUV S1, T1 ) and (03-05 Hummer H2) and (04-05 Cadillac CTS-V DB) and (98-02 Chevrolet Camaro FB) and (97-04 Chevrolet Corvette YB) and (98-02 Pontiac Firebird FB) and (04-05 Pontiac GTO VB)

The following diagnosis might be helpful if the vehicle exhibits the described symptoms.

Condition/Concern:
Check Engine Light with a P0300 due to 2 - 4 cylinders misfiring on the same bank of the engine. DTCs P0171, P0172, P0174 or P0175 may also set for the misfiring bank.

Recommendation/Instructions:
If the published misfire diagnostic does not isolate the cause, perform the following suggestions as necessary:

• Perform a fuel injector balance test for all 8 cylinders. If a fuel injector concern exists, it is possible to misfuel an entire bank of the engine, causing multiple cylinders on the same bank to misfire even though the root cause is a single fuel injector.
• Inspect O2 sensor connections on the misfiring bank for corrosion or water intrusion. If water intrusion is found on the right bank, it may be due to the AC Evaporator Condensation dripping onto the O2 sensor harness. If this condition is found, reposition and shield the harness to prevent a repeat concern and repair the connections.
• Check for excessive exhaust backpressure using the restricted exhaust diagnosis.
• Swap the Position 1 O2 sensors side to side to see if the misfires move to the other bank of the engine. If so, replace the O2 sensor.

SOURCE: poor idle dtc P1151, P1131,P0174, P0171. runs ok

Change plugs, and Mass Air Flow sensor. This should do the trick