Code 0304&0505 skips runs better after idle

THROTTLE POSITION SENSOR, MISFIRE, #4 MISFIRE, KNOCK SENSOR, THESE ARE YOUR TROUBLE CODES, PO120,PO300, PO304, PO325, RESPECTIVELY, REPLACE THE TPS @ THROTTLE BODY, REPLACE KNOCK SENSOR , @ ENGINE BLOCK, REPLACE YOUR SPARK PLUGS & PLUG WIRES ! AND YOU MUST ALSO REPLACE BOTH YOUR AIR & FUEL FILTERS, DISTRIBUTOR CAP & ROTOR , INSPECT, MAY NEED TO REPLACE, I WOULD ANYWAY !!!!!!!! ADD SOME GOOD FUEL INJECTOR CLEANER TO TANK, NEXT FUEL UP !

I'LL TRY, GOOD TO SEE SOMEONE TRY AT LEAST ! IDLE SEEMS HIGH, BACK TO BASICS !!!!!! THE AIR & FUEL FILTERS NEED REPLACED, SPARK PLUG WIRES, YOU FORGOT THEM !!! DISTRIBUTOR CAP & ROTOR, YOU FORGOT THEM !!! THESE ARE AS IMPORTANT AS THE AIR WE BREATHE !!!!! VACUUM LEAKS, CHECK ALL VACUMM LINES, THOROUGHLY ! THIS LINE COMING OUT OF THE TRANSAXLE PORTION OF THE INTAKE MANIFOLD ?????????????????/ YOUR NEED TO REPLACE WHATEVER IT IS, WHAT KIND OF LINE ? METAL, RUBBER , WIRE ??? MOVING ON, GOOD YOU REPLACED THE OXYGEN SENSOR, & IDLE AIR VALVE, & TPS, RECHECK TPS, IS IT LOOSE, ALSO TIGHTEN THROTTLEBODY BOLTS, THE ONES THAT HOLD IT DOWN. SO, CHANGE YOUR FILTERS,WIRES, ETC., MENTIONED ABOVE, CAP & ROTOR, ETC.,ETC.,.........GO FROM THERE, SEE HOW THAT WORKS

Have u checked the cadeletic converter. It can do funny things

Dirty throttle body, IAC sensor.

Have you checked for a vacuum leak? Be suspicious of the solenoids you see with vacuum lines going to them. I think it has 3 or 4 of them. don-ohio

Well,check for a vacuum leak,by starting it cold,and have someone keep it running while you spray some brake cleaner aT VARIOUS SPOTS WHERE VACUUM LINES MEET,or toward back of intake manifold,but not near air cleaner.
Any change in rpm down or up indicates a leak. don-ohio

Replace the pick up coil in the distributor,this is the problem.

It sounds like you did not change those intake manifold gaskets and they are not completely sealing the intake and causing a vacuum leak and the MAP sensor will read high in voltage and cause the bad idle.

Spray the intake with carb cleaner to find the vacuum leak. Check where the EGR mounts and the throttle body gasket sense you had both off.

My problem was solved when I repaired my 4 wd activation dash switch. The switch was contacting on 2WD & 4HI at the same time. The front differential activation is vacuum activated possibly creating a tug of war that didn't actually engage it but drained off vacuum from the engine? A theory at best but stumbbled across it because I knew the switch wasn't working properly I repaired it and low and behold rough idle disappeared and all is good for 3 weeks running.