Why do people think that either/both buying their own parts and/or diagnosing their vehicle's problems is going to make the repair cheaper? An o2 sensor won't fix a 25% ltft lean bank code if the original sensor is reading properly.. perhaps I should install it anyway, asshole/know it all tax. No I won't because it's not going to fix/change anything. And they bought bottom of the barrel brake pads to boot. Smh.
When I get a business/people to do work for me, I tell them what I want fixed, and expect it fixed right, but I don't tell them how to do it (aesthetics excluded)