Catalytic Converter Replacement Instructions?

The PO420 merely means your Catalytic Converter is not chemically doing what it's supposed to. This does not effect engine performance in any way unless the Converter is plugged up too. Here is a guide to help walk you through the replacement steps with instruction in the diagrams below to show you how on your car:

https://www.2carpros.com/articles/catalytic-converter-replacement

Check out the diagrams (below). Please let us know what happens.

Just to add to your overall question, using that itrip probably did not cause this. The best way to tell if these things cause issues is to just unhook them and if the vehicle returns to normal then it is related. However, I highly doubt it.

Let me know if you have more questions. Thanks

Good morning,

You can verify the Catalytic Converter being bad by monitoring the O2 sensor reading at the cat or the downstream.

Watch the voltage readings as they should be stable at about.476 to.5 volts. If the voltage goes up and down more than.2 volts, the cat internals are worn out and needs to be replaced.

Roy

The oxygen sensors might not be switching properly and causing the converter to lit up the unburned fuel creating all that heat-

Causes Of Converter Failures

Fouling, clogging, melt-down and breakage of the ceramic substrate inside a converter are common conditions that can cause problems. Plugging is usually the end result of a melt-down, which occurs because the converter gets too hot. This happens because the engine is dumping unburned fuel into the exhaust. The excess fuel lights off inside the converter and sends temperatures soaring. If it gets hot enough, the ceramic substrate that carries the catalyst melts.

The unburned fuel may be getting into the exhaust because of a bad spark plug or valve, but an overly rich air/fuel mixture is another possibility. In older carbureted engines, a heavy or misadjusted carburetor float may be the underlying cause. But on newer engines with "feedback" carburetion or electronic fuel injection, the engine may not be going into "closed loop" (the normal mode where the computer regulates the air/fuel mixture to minimize emissions).

A bad oxygen sensor or coolant sensor may be giving the computer bogus information. A sluggish or dead O2 sensor will make the computer think the exhaust is running lean, so the computer will try to compensate by making the fuel mixture rich. A coolant sensor that always indicates a cold engine will also keep the system in open loop, which means a steady diet of excess fuel. But it might not be the sensor's fault. A thermostat that's stuck open or is too cold for the application can prevent the engine from reaching its normal operating temperature. So if your converter has failed and needs to be replaced, the engine should be diagnosed for any underlying problems before the new converter is installed.

Another cause of converter clogging and contamination is excessive oil consumption. Worn valve guides or seals can allow oil to be sucked into the engine's combustion chambers. The same goes for worn or damaged rings or cylinders. Oil can form a great deal of carbon, and metals present in the oil can contaminate the catalyst. A compression check or leak-down test will tell you if the rings are leaking, while a fluttering vacuum gauge needle will help you identify worn valve guides.

Very possible the CAT is clogged, they are very sensitive to impacts, that is, if it was dropped or hit it could break the material inside.

Return to installer and have it removed and checked for broken material.

If clogged and backpressure is too high car will not start, or if it does it can damage valves.

Hi W. Shore,

Ok, I believe you are talking about the Exhaust Manifold. And the only reason I can think off for it needing to be fixed or replaced would be do to it being cracked. And $1,100 is way to much to replace it. The Exhaust Manifold shouldn't cost but about $120 and labor depending on the rare in your area shouldn't be more than a couple hundred.

Now, if it is the Intake Manifold then yes $1,100 is a fair price. But again the only reason to replace it would be because it is cracked.

So, I would contact the garage and make sure of which they are speaking of. Then I would call around and get a few other estimates.

.