I have a vsc light and vsc light off on too,plus it idles really low like it's going to die but doesn't,it has a awful rattling sound coming from exhaust somewhere. the cat.converter has been changed and exhaust coming off motor has been cleaned out,plugs have been changed & it doesn't have plug wires,by the way it's a 1999 lexus es300 w/180,000 miles on it,please help me!!!! thank you!!!

I would look under the car mid way for an exhaust leak.There will be an oval shaped clamp with 2 studs about 3`` apart on the side of the catalytic converter holding a wired sensor in place. Check to see if you have an open exhaust sensor port or burned out gasket with your sensor hanging off the pipe. If so the sensor has vibrated loose and is sucking in fresh air and throwing off the emission sensors in the engine. If the sensor is hanging off and you drive, the wiring could break and you might lose the entire device.$$$$
I was driving my RX300 last week and it literally just started to sputter and the sensor fell off the studs, the nuts had rotted off from heat... Easy fix for me luckily a gasket and 2 new studs , but I had to have the dash lights reprogrammed ans well.
Please post back to advise