peartjar

Update: After multiple trips to the dealership where they couldn't duplicate concern I found the exhaust leak myself. I used a CO meter and traced it to under the passenger side (by the exhaust, obviously). I put my hand near the clamp just following the catalytic converter and before the flex pipe. Exhaust was puffing out of that. To me, this explains why the smell is only after cold start because once the cat warms up and def starts flowing the exhaust gets treated and smells less like raw diesel. Heres a picture of the clamp, and a link to an article that discusses the leak. Why couldn't the dealership find this? https://gm-techlink.com/?p=13781

I also have a raw diesel exhaust smell in the cab & under the hood 2021 Silverado with lm2. It’s strongest on cold start, but i can still smell untreated exhaust smell if I pop the hood when warmed up. Smells like a jet in the cab. Dealer replaced back pressure valve, but smell is still there. When I open the hood, smell seems to be strongest near the turbo (although it’s hard to pinpoint origin). Had this looked at 3 times. Not sure what to do next.