Aftermarket Catalytic Converters...Any Good?

I suggest that you replace oxygen sensor #1 (which is upstream from the catalytic converter) first, using the correct Toyota replacement part. A marginal oxygen sensor will not show voltage fluctuations as quickly (in response to changes in the air/fuel mixture) which may cause the engine ECU to log the DTC for a failed catalytic converter.

If that doesn't work, and you decide to install an aftermarket converter, you will have to separate the old catalytic converter from the HCAC chamber which is upstream from the catalytic converter. I hope that you have access to welding equipment or have a local muffler shop that will help you with this.

 

It is true that separate DTC exists for each oxygen sensor vs. the catalytic converter. Regardless, if the first oxygen sensor and catalytic converter are both marginal, the engine ECU may post the catalytic converter DTC.

Then, if the oxygen sensor is replaced with a new sensor that is quicker to respond to air/fuel mixture changes, the engine ECU may decide that the catalytic converter is OK. The ECU makes this decision based upon the difference in voltage readings provided by the two oxygen sensors (the first sensor is supposed to provide rapid voltage variations while the second is supposed to provide relatively slow variations, which indicates the cc is working.)

In any event, it's up to you. Good luck.

 

Go to a Meineke. I took mine there and was treated well, and the repair was cheap. Use the search function for my other post on this topic around here somewhere.

 

I just bought a 2002 Prius about a month ago, 223,000 miles. It had the P0420 code so I needed to replace the converter. I found a thread on this forum with instructions for replacing the cat with an Eastern replacement. It was pretty easy. I needed to cut the pipe right behind the 2nd O2 sensor and with a new donut seal for the inlet and a muffler clamp (included with the cat), I had it installed in a little over an hour. I cleared the code and no more CEL

 

Can you help me find that tread? Where did you purchase the Eastern replacement?

 

Don
Maybe this:
http://priuschat.com/forums/generation-1-prius-discussion/72037-2001-catalytic-questions.html

or this one:
http://priuschat.com/forums/generation-1-prius-discussion/86004-p0420-technical-aspects.html

I have the P0420 code on my '01 right now. Time to do more research.

Good luck.
Steve

 

Don, if you have a 2004, there is a direct fit available from Eastern. But it would be good to understand why your converter failed in the first place.

 

I haven't purchased the 2004 Prius yet. It has 250k miles. The owner/seller tells me the check engine light is for the catalytic converter. He had it checked at two different places. I will check the tailpipe for carbon deposits. He has been up front with me. I will also ask him about oil consumption.
Thanks

 

Here's the link to how to replace the cat in a generation 1 Prius: Prius 1st gen - Replacing the Catalytic Converters

 

I had mine replaced by a local shop ($50) after ordering the Eastern unit online. My MPG went up about 1-2mpg after the repair.