my 93 Ls 400 has 148000 on it had timeing belt replace full tune up plugs,wires ,cap rotor, kn air fliter,vales adjusted,, fuel filter,t body i cleaned with spray,. car runs great but when its cold hit the gas it great,but whe n its hot it pings and not great pick up i used hess 93,i put in lucas fuel inj cleaner,about 3 times . help no codes , i change the 02 sensors all 4. :(