At wits end

hi my 94 Cherokee started throwing 24 code. replaced tps, crankshaft sensor and replaced ecm..tested tps good..cleaned up everything ...sometimes check engine light will come on..sputters and bucks..other times no check engine light runs great.light comes on when driving down road starts acting up...stop at store..start up no light runs great till light comes back on...I'm at wits end...any more suggestions..tks