No. If your Cat. is plugged up the car will start but then die. Any other problems it won't prevent it from running. It might not run well but...
Yes a blocked exhaust will keep the engine from starting
Yes, a faulty catalytic converter can cause fuel consumption to raise. Replacing a known bad catalytic converter will help, but keep in mind, the catalytic converter usually does not fail on its own. converters are pretty tough, living their lives running at 2000+ degrese internally. I would check your EGR valve and EGR valve tube for blockage or carbon build up. a faulty or clogged EGR valve will overtime distroy a catalytic converter. second thing to check is your Oxygen Sensors. these sensors are the computers first reading of bad fuel mixture, if they are clogged with carbon, they can distroy your EGR valve, which inturn kills your converter.
NO
According to the Environmental Protection Agency, the installer must keep a replaced catalytic converter for 15 days after you replace it. They are required to keep copies of the invoices and statements for each after market converter for six months after they are installed.
try cleaning or replacing the cylanders
Buy a new one or keep beating the crap out of the one that is clogged.
yes keep o2 senser installed then no prop
Yes it is as it is to keep the noise level down.
To keep the car running - not at all. To minimize the amount of polluting exhaust - very.
I have seen a faulty boost sensor keep the turbo from "kicking in" but it didn't stop the engine from starting.
My understanding is that EPA requires a shop to retain possession for 15 days from the date of installation.
the cat is a short term for the catalytic converter. An exhaust system component. It helps to keep pollutants down.