A cordless drill with a very long drill bit makes quick work of the catalyst material. It'll come out in huge chunks once a few holes are drilled in it. The best delete pipe is one that doesn't look like a delete pipe.
Its a ceramic looking honeycomb with extremely small holes. The biggest problem is soot building up and clogging the holes, since the material itself doesn't change as it does its job. That's why it is so valuable, a catalyst isn't consumed it just spurs other materials to chemically react in its presence. Old converters have the soot and rusty metal removed and the powder goes right into a new outer shell. The feedback line is designed to introduce more oxygen into the converter to assist the catalyst in chemically reacting more pollutants. The increased oxygen was considered a good thing until fuel injection systems starting to rely on oxygen sensors to control the percentage of fuel vapor injected. Its no longer necessary when severely rich or lean conditions are eliminated and its not even an option on modern cars with a downstream oxygen sensor. A universal catalytic converter comes with a cap on the input line to be used with fuel injected motors. Once you remove that cap you have an exhaust leak unless it is connected to a system designed with a one way check valve to prevent exhaust from coming out.
Specifically the increased oxygen was said to react with unburned fuel particles and cause a secondary combustion that would heat up the converter, in turn increasing the effectiveness of the catalyst with the higher internal temperatures. The hotter your catalytic converter is, the more likely harmful secondary outputs like NOx and carbon monoxide will react to form harmless water vapor or carbon dioxide. That means that capping off the OEM converter input or having an inoperative pulse-air system will decrease the temperature of the catalytic converter, not increase it. Only soot buildup and the resulting restriction and back pressure can cause an increase in temperature, but its effective enough to make the catalytic converter get so hot that it glows red before its bad enough to stall the engine. This link doesn't offer much in the "Air Injection" section, but for what its worth it does support the statements I made.
http://en.wikipedia.org/wiki/Catalytic_converter The converter starts to get super hot during operation long before it puts so much back pressure on the engine that it stops running well. My Jeep Cherokee had a rug fire as a direct result of the converter underneath it. That happened around 230K miles on the OEM converter, before we could tell the engine was struggling. Thankfully it was my third car fire, so a fire extinguisher was on hand. Obviously I've learned the hard way to replace them at least every 150K miles. At night I walked past our Eagle sedan once and the ground was glowing because the converter was cherry red. Replacing that one made a huge difference to the engine, but it was the threat of fire that motivated us to do it.
Topic: Looked under the Eagle, got a surprise (Read 17217 times)