The dreaded 'check engine' light on my 1997 Civic hatchback came on\nFriday night. FInally got a hold of a code reader and it's reporting\nP0420. There were no other codes. Looks like the cat is past due... :-(\n\nI am in Canada and am wondering if this is under the extended emissions\nwarranty. I ask because the last time the 'check engine' light came on,\nit was P0171 (system too lean). I replaced the oxygen sensor at a local\ndealership. My wallet and I were surprised it didn't qualify for the\nwarranty. Supposedly only a cracked exhaust manifold would qualify...\n\nAnyhow, I'll be contacting both the dealer and Honda shortly. If it's\nnot covered, I'll be looking at getting a universal/OEM put in by an\namateur mechanic friend of mine. After Googling around, we'll be sure\nto check if it isn't the other O2 sensor just before the cat.\n\nInterestingly enough, we did not reset the code and on my way home it\nwent away... Any other suggestions? Heck, a link to this mysterious\nextended warranty would be appreciated. Thanks!