Lexus Sc400 Sputtering Problem

[holotoftrouble]

hi everyone ,im new to this site and need big time help,i have been reading alot of post,and there all similar to mine,its a SC400...here's my problem

ill be driving for a while,like 2 hours then shut the car off,start it right up again and then it starts puttering,like i press the gas and its not getting there,then all of a sudden it start ridding good again,sometimes it could ride good for 2 days but then its back again,almost like when it gets too hot,ive changed alot of parts,ECU pump,cap ,rotors and plugs twice,temp sensor,coils and more,i haven't check the fuel pump,but im doubt it would be that,,,any help would be appreciated,tks

[teb91]

You may want to do a resistance check of the coils when they are hot. For months I had an intermittent stall, bucking at speed, check engine light with no code, and like yours it would run fine for a few days even a week or so. Finally threw a code for all 4 oxygen sensors. Only common for both banks is ignition and each coil fire plugs on both sides. Found the left coil had resistance of 16ohms when hot where normal is 10-14. Changed the coil and its been fine for 4 weeks now. This is a 92 SC400, hope this helps.