2016 silverado owner …. Already rebuilt transmission, condenser replaced… I’m at 92k and my truck is running like ******, ended up changing the spark plugs and 2 of them were in VERY bad shape, surprised the check engine light never came on… but manual says change at 90-100k but my mechanic hommie said 45k… but it was the 2 back spark plugs #4 and #8.. almost the same issues as bad torque converter and transmission