Hello people Sierra 2Liter OHC Bj.1992 Code to 2-0928 to 3-669 When riding uphill no power engine does not pull. CO values at 4.5% Lamda probe does not renew Kat kaput according to the worksstat.Can it be that the cat is already so clogged that does not go through anymore ??? or can there be other reasons zbw injection, detonation etc. For reply very grateful Diablo 4085