Big_Eight

Awesome! Thank you for looking.

I ordered and upstream and downstream oxygen sensor from Rock Auto and picked the genuine GM Part option. The upstream (ending in 516) says Denso on it and the downstream (ending in 188) says NTK. Are Genuine GM parts not AC Delco anymore it kind of looks like maybe AC Delco is having these parts made for them? If not that's fine, I just want to make sure I'm not getting taken. Thanks for your help on this everyone. This is for a 2014 Silverado with the 5.3l Ecotec3.