Hello Folks,
new to this group.
I have a 2014 silverado 4x4 5.3 V8 crew cab short bed 180,000 miles
About 4 months ago i started getting several check engine codes related to 02 sensors and cats.
i had a shop replace all o2 sensors one at a time until all lights codes were resolved. 40 miles later i started getting the P0430 code for catalyst below efficiency threshold bank 2 side 2
The shop ran several diagnostics including checking MAF and MAP sensors. replaced the Map sensor and cleaned the MAF, checked for exhaust leaks (none found) checked injectors (correct Pressure) checked 02 sensor readings (readings were ok per the diagnostic computer), ended up replacing the cat converter on passenger side. reset computer, drove it in the recommended break in cycle per tech bulletins. withing 40 miles the same 430 code was back on. after over $1500 in expenses already i took it to another shop. again all the above diagnostics were performed. we changed out both 02 sensors on passenger side with a higher quality sensors. light still came back on within 5 miles. we decided with no other good options that we should change out the new cats (300 miles on them by now) with magnaflow cats to rule out bad parts. reset light drove it again the recommended cycle. within 20 miles same dang code was back on. i am also eperiencing a code for low oil pressure P0521 i think. we have not fixed this yet. it was determined that it is a bad sensor for that as well. both highly skilled mechanics are out of options. what are we missing and could that low oil pressure sensor somehow be affecting this exhaust code. Help i am in over $2500 with no solution yet.
