Interesting post. I had a P0420 pop up, and the Auto zone guy told me it was b/c it was a sea-level car (Atlanta) and I just moved to Los Alamos (8300 ft). Hmmm. Would thinner air make a P0420 come up?

Munch 12/99-04/03: 98 SE V6 MTX w/ "reliability mods" 04/03-: 02 Taurus