Hi Folks,

I read a few posts, I have my service manuals but I haven't been under the car much. Yesterday morning while going from 30-75mph in a blink of an eye, I heard something hit the bottom of my 96 z28 and when that occurred, the Service engine light came on. The car ran fine for the next 50 miles. It ran fine on the way home too. I plugged in and saw P0420. I noticed my hwy MPG has been lower than years ago; currently ~23mpg whereas I used to get 31mpg. Did I just toss an oxygen sensor or just hit a rock? Will I be able to see and work on the right and left bank O2 sensors from the top of engine? Dang! It's chilly outside. I'll have to use the engine as a hand warmer...

Jim

 

P0420 is for low cat converter efficiency on the drivers side. Could be a damaged sensor, could be a damaged converter.

 

Happy New Year. I wasn't able to touch anything over the holidays. My shop manual said the check engine lite will reset after 3 good runs that have no issues. The lite shut off yesterday. It runs great and did all along. If the lite failed which may cause a catalytic converter to clog and upstream engine issues... I guess I'll focus a time making space in my garage replace the clutch too. I have 120k on it. I think I hear the throwout bearing when I'm at 3000 rpm. Sounds like a turbocharger. Any idea how long till I hear my bell housing ring?