Replacing Catalytic Converter

[tomj76]

I bought the Direct replacement converter by Walker, and put it on tonight.

Issues that I found:

1) Two O2 sensor holes are located wrong, such that the pre-cat one for the rear bank interferes with the nut that holds it on the exhaust manifold. I got it on and tight, but I'm afraid that it will be difficult/impossible to remove in the future. The O2 sensor in the post-cat location for the front bank was also located wrong and the sensor wire will not reach the connector when it's on the holder clip. I had to take the connector off and let it hang loose.

2) The flange to the extension pipe on the OEM part had tapped holes, but the flange on the Walker is not tapped. I had to come up with some nuts to make the connection.

3) There are no heat shields. Walker claims they are not needed.

4) A hanger rod is on the converter that is not needed and interferes with the transmission.

I checked the part number and it was the right one. It's just not done very well. I'm considering taking it back when I have a chance, due to manufacture's "defects".

Has anyone else replaced the converter with a direct fit? Any recommendations?

[wiswind]

I used the Walker direct fit unit about 4 years ago.
I found the same with the flange to the flex pipe at the back....and had to come up with a couple bolts & nuts.
The oxygen sensor locations were fine for my '96 3.8L.
I needed to trim the support tab that bolts to the transmission....so that the tab did not extend over the tranny pan.
I would have liked for the neck to the front exhaust manifold to have been a tad bit longer......as the top of one of the converters touches the oil pan.

It took something like a MONTH for the PCM to set for the downstream oxygen sensors.

All in all, the unit has worked fine for me for quite a while......and a lot of miles.

The BEST replacement would be the OEM.....which for the '96 lists at about $1600, and the cheapest that I could find it online was about $1200.
This is just for the "Y" pipe assembly......not installation.
Compared with $329-$350 for the Walker direct fit unit.

[tomj76]

Thanks for the response. You're right about the price difference. However, there are some intermediately priced direct fits available too. (~$700). Also a Magnaflow direct fit cat can be purchased for about the same price as the Walker.

[wiswind]

There may be more available now....I have not researched this recently.
I do know that the unit from Napa that was $450 at the time looked IDENTICAL to the walker unit.
I did a LOT of looking online......and there were not many options out there at the time.
Another member, Searcherr, used a magneflow unit.....as I remember.....and had some similar issues with it relative to the oxygen sensor mounting locations.