ok afterschool i left my school... i was on my way home. all the sudden my car's exhaust (Greddy sp2) started sounding like ****... and TONS of white smoke was coming out of my car when i was stopped and my car was idling low... causing it to shake wicked bad whenever i was stopped or slowed down. and when i accelerated it was not smooth at all... i came home and look at my tires and saw that i ran over a peice of metal with the back driver tire... could just that tire with the metal in it be the cause of all that?

 

No. What did you run over

 

i dunno... it looks like a flat peice of sharp metal or something

 

could the catalytic converter be bad?

 

White smoke and bad idle sounds like a blown head gasket to me! Ouch

 

is your check engine light on?

 

it was before... for my knock sensor, engine coolant temperature sensor, and crankshaft position sensor... i replace the engine coolant temperature sensor... which fixed my starting problem a few weeks ago, and now this crap comes up... currently, my check engine light is not on, i cleared it after i replaced the engine coolant temperature sensor

 

is there anything i can do to check it? or should it only be done by a mechanic? and if a mechanic did it for me, how much would it cost to replace and for labor?
thanks

 

im starting to think my catalytic converter may be blocked or clogged... because i just took it for a run and it did not burn a giant white cloud of smoke like before... it took a lil while to get it started though...