My car is throwing 4 codes PO171, PO174,..PO741, PO300. What parts should i buy?

did you bleed the air out of coolant system after doing the work?before you go to throwing parts and money at your car,check for vaccum leaks,engine area,all of them.also check the transmission fluid level.check to see if all your coils have spark.while you are at it,check your mass air flow sensor to see if the little bitty wires are black or discolored.if they are,try cleaning them with mass air flow sensor cleaner,only.remove it,spray wires gently,they will break easy.let dry,reinstall.see youtube video.post results

Fix the engine overheating problem *first*....and go from there!

P0171 & P0174 It's very likely that the problem is caused by an intake leak. If there are no intake leaks, the next step is to replaced the air filter and clean the air flow sensor (only use MAF Sensor Cleaner!!). If the problem continues, the front oxygen (O2) sensor may need to be replaced. P0741 More serious, and I'm sad to say, transmission related. You have bad seals inside of your transmission. What causes this is a loss of seal in the channel plate, which causes a loss of the fluid pressure used to engage the converter clutch. This causes the PCM to overstimulate a solenoid, which eventually fails/doesn't work properly. You can replace the TCC PWM solenoid, but its only temporary. You have to replace the seals inside the transmission first for a permanent fix. P0300 A cylinder or multiple cylinders are misfiring or randomly misfiring. Start by checking for intake leaks (intake gaskets are a common cause for multi-cylinder misfiring). If no leaks are found, the next step is to replace the spark plugs. As for the overheating... To be honest, it could be many things from air bubbles to a wrong temperature or defective thermostat...