failed emission test, too much polution Options

[celestrial_rider]

so my '94 celica gt failed its emission test again (2nd time) this past week. it gave me the same reading that im making too much CO. i changed the oil, oil filter, air filter, sparkplugs, even poured in a bottle of seafoam into a full gas tank..and it still fail. i was given a few options b4 my next emission..either i replace the knock senser, or replace the O2 senser (a buddy recommended either, or both). just curious if u guys can piont out anything else that might b causing this high level of polution..just anything. thanks.

[x_itchy_b_x]

pretty soon the states will lose their right to govern there own emissions.
soon one law with rule all the states because of global warming. fun stuff huh.
was watching it on CNN.