Let us spray. 1  When you're at the perfume counter, buying something smelly for your nearest and dearest this Christmas, just don't ask what's in it. 2  When you're at the perfume counter, buying something smelly for your nearest and dearest this Christmas, just don't ask what's in it. Hannah Betts argues you may get a nasty surprise.
Best Answer: When a catalytic converter goes bad it will restrict the flow of exhaust gases through the exhaust system. Basically, if the exhaust won't come out easily, air won't be taken into the engine easily to mix with the fuel to be burnt and give you power.
A bad sensor will be flat-lined and show no response to snapping the throttle. Test for O2 sensors behind the catalytic converter: Graph the rear and the front O2 sensor output. Rev the engine to approximately 2000 RPM. The front sensor will be oscillating actively.