Why is there a heat.shield on the upstream sensor? Why isnt it just a bit larger so I can actually get a tool on it? I'm trying to do a.back pressure test to see whether the catalytic converter is clogged. I ran thru some large puddles and I'm now getting code P0420. Im thinking I broke the Cat.
Why not just unbolt the cat back and run something like a fish tape see if you hit the brick . That's a stretch. Unless ya smashed the converter into ground or asphalt or such . Breaking cause of fast cooling ? Meh
