how do i fix it 1994 Pontiac Sunbird le 3.1 liter v6?

[convict2008]

it starts up fine runs good good power but go dwon road 8 to 10 miles it shuts off wen it cools it starts and runs it seems like wen itgets hot it shuts off its not overheting im not shore what it is but ned to fix please help thank you

 

[bob67cam]

sounds like yer catylitic convertor is plugged
take a sawzall and cut right before the cat ..it will be loud but see if u make it 20 miles or more..if so remove the cat and throw in a chunk of pipe...just dont tell the eco nutz out there or theyll try and shoot you im sure...
in fact im probly endangering my life by telling you that.use it wisely

 

[baldie]

a coil will do that when it gets hot and breaks down.