rich air/fuel mixture

There are a handful of telltale signs your catalytic converter is on the fritz. Poor acceleration when stepping on the gas pedal Noticeably less fuel efficiency Dark, sooty smoke exiting your muffler Engine starting trouble Failing an emissions test A pungent sulfuric or rotten smell A Check Engine light in conjunction with any of these

Got questions?  We’ve got the answers—the Summit Racing tech department tackles your automotive-related conundrums. This week, we’re diagnosing carbon deposits on an exhaust system and resolving a rich air/fuel mixture. J.K. • Mountaintop, PA Q:  My 1970 Buick Skylark has a 350 Buick engine, a 350 turbo/hydro-automatic transmission, and a Chevelle 12-bolt posi rear-end. I