Service Engine Light On problems of the 2013 Chevrolet Silverado 1500

Truck was purchased certified pre-owned in June 2017, in June 2018 problems arose including rough idling, service engine light activation, and stabilitrak off message activation on the dash readout. General motors (gm) technical service bulletin (TSB) #10-06-01-008m was issued December, 2014 to address the repair for this problem. The issue was motor oil reaching the #1 and #7 cylinders thus fouling those two spark plugs. The truck was repaired under the extended warranty. The same symptoms appeared again in August 2020 and the chevy dealership diagnosed the same issue (mis-fire in the #7 cylinder) as described in the TSB. Since the vehicle was no longer under warranty, gm would not pay for the repair. I chose to deal with the symptoms myself which involved installing new spark plugs in the two cylinders. In mid-March of this year (2021), the symptoms appeared again and again the #1 and #7 spark plugs were fouled with motor oil. In each case, the vehicle was in motion when the symptoms presented. It's my understanding that stabilitrak is designed to help prevent accidents by giving the driver better control of the silverado. If a service stabilitrak warning appears, the silverado will no longer be assisted when a loss in lateral traction is detected. Additionally, the rough idling affects acceleration (loss of power. ).