GrandPrix34 Posted December 22, 2003 Report Share Posted December 22, 2003 wat are some symptoms of a bad cat converter? the car runs but it hesistates from a stop, exhaust smells like rotten eggs How can i check for a bad cat Quote Link to comment Share on other sites More sharing options...
Redfox340 Posted December 22, 2003 Report Share Posted December 22, 2003 How can i check for a bad cat The smell is a first indicator, but after driving look underneath the car. If the cat is smoking, or glowing red from the heat of combustion, it's has a minor clog in it. If the car fails to idle but runs when gas pedal is applied, it could be a severely clogged cat. When cold, if the cat rattles when shaken, the internals are breaking apart and can create future issues. - Erik Quote Link to comment Share on other sites More sharing options...
Slade901 Posted December 22, 2003 Report Share Posted December 22, 2003 Another way a cat becomes clogged is that it turns into a big clump where the carbons have blocked all the honey comb mesh inside the cat and you don't hear rattling. Get a back pressure gauge $27. I would get a Seafoam Motor Tune-Up from Napa. It gets rid of most carbon build up in the engine and cat. 1/3 in fuel tank, 1/3 in oil crankcase, 1/3 in intake vacuum through the brake booster (you need to remove the brake booster and put a funnel and pour it in there while the engine is running). Turn off the engine after the seafoam is empty. Let is sit for 30 minutes or more. The longer the better. I recommend driving the car at night at less traffic highway and put the throttle at WOT and it would cause a lot of smoke which is normal. See if that clears the cat clog and if not it clears your carbon buildup anyway and then do an oil and oil filter change. Quote Link to comment Share on other sites More sharing options...
Intlcutlass Posted December 22, 2003 Report Share Posted December 22, 2003 Also , don't the exhaust manifolds glo if your cat's all plugged up? Quote Link to comment Share on other sites More sharing options...
tomz34 Posted December 22, 2003 Report Share Posted December 22, 2003 Another sign of a blocked cat is loss of power when pulling on a steep upgrade, with a rotten egg smell. Also if its severe you will see the outer shell of cat glowing after a long ride. Quote Link to comment Share on other sites More sharing options...
supreme_style21 Posted December 23, 2003 Report Share Posted December 23, 2003 My cat has melted into a solid chunk. There was/is no smell coming from it. The only thing I've experienced is a loss of power, supposedly from the backpressure caused by the solid cat. Quote Link to comment Share on other sites More sharing options...
cutsup1996 Posted December 23, 2003 Report Share Posted December 23, 2003 check the O2 sensors first, how long since they been replaced, bad ones can cause a smell too, mine did, also I heard of the dollar bill check for a bad cat, put a dollar bill up to the exhaust tip about 1/2 inch away while car is running, if it is intermittently sucked back against the tip then the cat is bad Quote Link to comment Share on other sites More sharing options...
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