why did it take 70 miles of driving dor ck eng lt to come on

Question

the cat was replaced all 4 o2 were replaced ck eng light came on after 20 min. so replaced  the 2 front o2 sensors again after air fuel trim test. drove 70 miles and light is back on with  po 1133 and 1135 codes where to go from here

Answer 1

Slow response from the front 02 sensor, GMC 02 sensor goes to slow response if there was a misfire condition, or a MAF sensor that is reporting incorrect incoming air, Try a MAF cleaning only and clear the code , clear the code regardless if  there is a CK ENG LT on by doing a code clearing regardless if the CK ENG LT is on this causes a resistance relearn of the H02S resistance.