Shakes or Wobbles problem
1997 Chevy Suburban V8 Two Wheel Drive Automatic 223336 miles
All of a sudden my vehicle started shaking like it was going to cut off. So then I had the spark plugs and wires change. I also put fuel injector cleaner in. The problem was still there. Then I started thinking that I put bad gas in my car because this started the day after I gas up. Now my car has a bad gas smell. Its NOT the foul rotten egg smell, but a loud gas odor. There is also a rattling noise underneath my vehicle that started a couple of days ago, and everyday its worse. I was told that it may be my catalytic converter. Please help shine some insights on my situation.
How many times have you had the catalytic converter replaced and if so when was the last time you replaced it. Is the coverter discolored or bulging anywhere? Use a vacuum guage on the manifold and run the car up to normal operating temperature. If the guage seems to slowly fall towards 0 Hg. And then rise back to 17-22 Hg. Then the exhaust is restricted. If it has been 60,000 miles then most likely you are correct that the catalytic converter is dead. By 60,000 miles the catalyst material has been significantly clogged with carbon buildup and will eventually clog the entire exhaust system. Usually this is a gradual process as the car will first recieve worse gas milage and then drivability; however, the catalyst honeycomb can collapse on itself and more or less fuse and melt together under the extreme heat from exhaust gases. Please note that an EGR valve can also cause problems similar to a plugged catalytic converter.