check engine light code

i have a 98 civic dx auto and it has check engine light so i decided to run the codes. i was wondering if u guys would help me out. it picked up 5 codes

1) p420-catalyst efficiency below threshold (bank 1)

2) p0301-cylinder 1 misfire

3) p0302-cylinder 2 misfire

4) p0300-random/multiple cylinder misfire

5) p1456- manufacturer control auxiliry emission control

well when i turn on the car for the first 10 sec. or so it acts like it wants to turn off like its choking or something but then after it reaches a higher rpm it goes back to normal, it also been wasting alot of gas recently but other than that it runs fine. hope u guys could help thanks

how many miles do you have on the car ? If under 80k the cat maybe still covered under factory warranty.if not p0420 means you need a cat .the p0300 reconizes there is more than one cylinder misfiring .the p0301-4 indicate the cylinder.the p1456 is related to the Evap system indicating a small system leak (check gas cap) .you may need a tune -up .

Forget about the P420, P300 and P1456 for now, those are the codes that
comes along with the 2 misfire codes. Your main concern is to find out what is causing your engine cylinder 1 and 2 are misfiring, once you fix that and clear the codes than you will be fine.

Check your cylinder 1 and 2 sparkplugs and wires first and see what you can find.