My check engine light came on 2004 ford taurus had a friend the plugged one of those code readers in got two codes po 174 and po 171 what do they mean

Does the engine rev and you don't move, if so have to check the transaxle. I'm not a tranny person.
If other, how long since a tune-up? Are there any applicable trouble codes? To check codes yourself, at the least, you need an obd2 code reader. Some of the national brand auto stores will check po codes for free. I don't know if they will check manufacturer specific codes?
There is more we could talk about, but, I need more info to know which direction?

code p 0300 refers to random /multiple cylinder/s ---misfire detected ===causes spark plug/s---HT lead/s ---injector/s --ignition coil/s ---low compression---wiring
code p 0316 refers to misfire detected during start up--first 1000 revolutions ===causes --engine mechanical fault ---wiring---ignition system---fuel system--injector/s
code p 0420 refers to cat converter system, bank 1---efficiency below threshold === causes cat converter---HO2S 2
code p 430 refers to the same problem and causes as code p 0420
Here is a news flash .
engines under the control of an engine control module (ECM) do not need you to do a tune up as it tunes the engine 60 times a minute and reports to you by fault codes when it can no longer tune up the engine

Code 316 means the engine computer has detected a miss-fire on startup. You normally get a code for the cylinder causing the problem.
If the spark plugs are original, I would start with checking them for signs of damage or excessive wear.

. code po305 is cylinder 5 misfire that can a bad spark plug or a injector.po153 is a o2 sensor. there is 3 on your engine. which one did they replace. the code po153 is for the front one it is in front of the radiator. code po443 is for the purge solenoid ,but there is many things the can cause the code the garage should have checked things first. wow

code p 0306 is misfire detected no 6 cylinder causes electrics
more likely a bad injector , injector wiring or dirty tip

Please go to this page for engine misfire causes.

EGR Valve

You can print all codes from
PO-011 thru PO804 on www.engine-
light-help.com/generic

Remember every vehicle has MFG
Specific Codes that aren't easy to find
and you will need them also

Call Auto Zone, they should be able to tell what that code is and the replacement part as well.

You will need to put your car on a diagnostic fault code reader. The engine malfunction light will come on if there is a fault with the emissions if it runs ok and isn't misfiring it's probably a oxygen sensor fault or a catalyst fault. The light won't go out unless the fault is cleared

P0300 maens random multiple cylinder misfire.
When was the last time the car was tuned.
Check plugs and plug leads are O.K
also check that fuel cap is on tight.