New catalytic converter question

[kendem]

My 240 failed the smog test about 4 years ago and they told me I needed a new cat. They cut the stock flanges and welded the new one on. About 2 years ago when I needed to get my smog test (every 2 years in Cal) my car failed again due to the cat. This time the guy said he could advance the timing to get it to pass and it barley did pass.

My question is, if I replace the cat myself, I guess I would have to weld a new one on because now I have no flanges to attach an OEM or a direct fit? I’m kinda of pissed that that shop cut my stock flanges.Any suggestions much appreciated...

[Cone Junky]

Unfortunately you are at the mercy of the last hack that worked on your car.I wanted to upgrade my cat and cat-back exhaust recently, but I had to track down a good downpipe from the junkyard because some hacks did the same to my car.

Aftremarket cats tend to be junk, but what are the numbers on the emissions. Unfortunatelt just because a cat made it pass in the past it may not, or have never been, your problem. A brand new cat can mask what your real problem is...

[carmo]

You may be able to buy just the flanges from companies like vibrant performance. If you can weld or have access to a welder and a friend who can weld this could turn into a cool DIY exhaust project.

[r3v_v3ng3]

figure out what caused the converter to fail, it should last the lifetime of the car

thats why alot of people change cat every other 2 years because they barely pass last time and almost all the time it will pass with a new cat. without finding out what caused it to fail last time, you will most likely to fail the next time you go for smog check

[kendem]

Much appreciated for the great suggestions. I will probably weld some flanges on myself and install an OEM cat.

The hack shop that installed the cat 4 years ago failed to cut the pipes short enough (about 2 inches) so my remaining tail pipe assembly coming out from the cat to my muffler was too long and hanging sideways on the rubber hangers. This caused the muffler to rattle against the body when the muffler heated up. I took it back to the hack shop 3 times because they didn’t know what the problem was. One of the BOZO’s thought my motor mounts were broken.

I finally looked under the car during the 3rd visit and saw what the problem was and pointed it out to him. And can you believe the BOZO wanted to shorten the pipe at the muffler still leaving the assembly hanging sideways? F#$@% Idiots!!!!!

Thanks for listening…..I think what contributed to the cat failing in the first place was the vacuum hose that connects to the underside of the EGR valve and BPT valve was broken for a long time and the computer was throwing a 32 error code. The cat was the original and was 14 years old at the time of the inspection. Since then I changed all the vacuum hoses and have not had any problems with the engine light coming on.

Ken

[480sx]

There are good aftermarket cats, you just need to stay away from no name ebay brands and your good to go.

A cat is a pretty simple thing.. They just get clogged, overheat, and then burn themselves up.

[kendem]

Thanks 480sx,I looked at Kragen's website and they have a maremont direct fit cat for about $130. They also have a maremont header pipe for about $150. Also they have the short tail pipe for $20. If I go that route all I would have to do is weld the end of the tail pipe to my existing pipe. Then when I burn out this cat I can eaisly replace it.

Ken