Do repair shops cover free check-ups? I wanna check backpressure and see if my muffler is still in working order. I hear a sort of puttering sound coming from the exhaust so I suspect some sort of leak somewhere, but I'm not sure if the mechanic will just drill a hole somewhere and scam me.
I know you can check pressure yourself, but I don't wanna drill any holes in my exhaust if I don't have to.