Replacement Catalytic Converters

[srgilbert]

I've replaced the front oxygen sensors and I am still pulling codes for weak cat on bank 1 or failed rear sensor bank 1. I spoke with my Lexus mechanic buddy and he shared that the 95 LS400 cats were a problem so when one that fails it is not a surprise at 100K miles. I understand that used ones are not allowed by EPA so I am looking for an aftermatket alternative. Can anyone help me on this? I understand that there are brands called Catco, Magnaflow and Copy Cat out there. Any advice on this one?

Thanks - really tired of looking at that check engine light.

[95LS400Bob]

You just have to look at Summit or somewhere like that and match some measurements that it will physically fit. Then a muffler shop will probably have to weld on flanges. Also some muffler shops might sell a generic converter. You are right on the used deals. A frined in town with a muffler shop said he has to keep close tabs on old cats he takes off and has to accoutn for them with the EPA. Some outfit comes around and buys them from him that has EPA approval.

[srgilbert]

I believe there are direct bolt on cats available. As an example they are currently on Ebay

http://cgi.ebay.com/ebaymotors/LEXUS-NEW-C...sspagenameZWD1V

or http://cgi.ebay.com/ebaymotors/lexus-ls400...sspagenameZWD1V .

I know very little about cats but these appear to be direct bolt ups. Going to the dealer is really out of the question.

Does anyone have experience with either of these? I believe CATCO - another option is a major brand.

Thanks

quote=95LS400Bob,Aug 2 2005, 12:26 AM]

You just have to look at Summit or somewhere like that and match some measurements that it will physically fit. Then a muffler shop will probably have to weld on flanges. Also some muffler shops might sell a generic converter. You are right on the used deals. A frined in town with a muffler shop said he has to keep close tabs on old cats he takes off and has to accoutn for them with the EPA. Some outfit comes around and buys them from him that has EPA approval.

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[95LS400Bob]

That is a good find and they say they will fit. If it is a bolt on replacement...and it reads like it is...that is what I would do. Even if they only last a couple of years you would still be ahead.

My P0 420 or whatever it is light ever comes back on....I will replace them for sure at that price. But it has been staying off on my car.

[chubyball]

I just replace my cat now the engine code is clear :) Man, I tell you.... It's great when the damn problem is gone.

If you have a bad cat you could smell the unburn gas somewhere around your engine while warming up the car. After replacing a new cat, the smell is gone.

[srgilbert]

Which brand did you use? Did you notice any performance improvement as well?

[chubyball]

I don't know the brand, I had a local ordered and replaced for me. The different is the car is moother on start up, idle in couple hundred lower, no bad smell from the unburn fuel.

[chubyball]

After I replaced the cat and reset the EFI1 and EFI2 by removed and pluged back the fuse from the fuse box. Now the engine code appear again after 500 miles -1000 miles driving. it's seem to be the same code P0420 but this time it does not say anything about Bank 1. Does anyone know what else code be wrong?

I also recently just had the AutoZone guy reset the computer by using the Scaner this time, instead of pluging off the EFI fuse.

[95LS400Bob]

This is why I have not replaced the cat to fix the P0 420 code. I removed the cat and it looked perfect. The car runs perfect and the PO 420 code just appears sometimes. Lately I haven't had the code at all even on a 250 mile trip. So I am thinking maybe it is just a glitch like the low idle deal..maybe ECU related.

[srgilbert]

I believe this could also be ECU related as the car runs just fine. Oddly enough the State of Illinois send me a card to have the LS400 tested. I'm thinking about deleting the code through a scan tool and letting them test it. I would think if the car passes this is a ECU problem - your thoughts?

[Jacob]

I believe this could also be ECU related as the car runs just fine.  Oddly enough the State of Illinois send me a card to have the LS400 tested.  I'm thinking about deleting the code through a scan tool and letting them test it.  I would think if the car passes this is a ECU problem - your thoughts?

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I have a 1996 LS400 that passed the emissions test about a year ago despite the P0420 and P0430 codes (I had light turned off before going to the test). And, the car runs fine…

[srgilbert]

Is the light back on again? I guess I can just use electrical tape to hide that light but I'd like to figure out what is going on. Seems like CATCO is one of the lowest cost direct fit options out there. ABout $155 a piece and I believe its like replacing a headlight - mind of well replace them both as the failure interval should be relatively colse.

[95LS400Bob]

I believe this could also be ECU related as the car runs just fine.  Oddly enough the State of Illinois send me a card to have the LS400 tested.  I'm thinking about deleting the code through a scan tool and letting them test it.  I would think if the car passes this is a ECU problem - your thoughts?

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Yeah. Clear the code and let them test the smog. The you would know.

[chubyball]

The Autozone guy told me that may be a leak at between the magnifold and cylinder head. To troubleshoot this problem, he suggests to use a torch with loose air and set it near the gasket, and make sure has the car running while doing in it. This way, we can figure out where the leak at.

I worry about blowing up myself even though the torch is not lite up. Your thoughts guy.

[srgilbert]

I am getting P0420 and 0430 codes which points to the cat or the rear sensor on Bank 1. If it were an upstream leak I would think that the 1st ox sensor would pick it up. I replaced both front sensors already as that was a cheaper way to determine if those which fail first could be causing the problem. I'll take it to the smog test station saturday after deleting the check engine light and see what happens. If I pass I will be really stumped....

[chubyball]

Let us know how thing turnout! After replacing the old cat, I see there were alot of gunk in the Bee nest, I guess it resolve one problem so far. Since I took so long (1yr) to replace the cat. Do you think think the ECU mess up?

My question is that the engine code does not appears right away on next day, but I have drove for 150 miles and the engine light has not been ON yet.

[95LS400Bob]

I am getting P0420 and 0430 codes which points to the cat or the rear sensor on Bank 1.  If it were an upstream leak I would think that the 1st ox sensor would pick it up.  I replaced both front sensors already as that was a cheaper way to determine if those which fail first could be causing the problem.  I'll take it to the smog test station saturday after deleting the check engine light and see what happens.  If I pass I will be really stumped....

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I bet it passes. With flying colors.

[BoyBlu70]

I am getting P0420 and 0430 codes which points to the cat or the rear sensor on Bank 1.  If it were an upstream leak I would think that the 1st ox sensor would pick it up.  I replaced both front sensors already as that was a cheaper way to determine if those which fail first could be causing the problem.  I'll take it to the smog test station saturday after deleting the check engine light and see what happens.  If I pass I will be really stumped....

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Yeah get rid of the code it should pass with no prob my 1990 did something like that. But now I think I'am having the ECU problem my 1990 LS400 will not idle at all it did have a high idle about two months ago then it started to get lower and lower until the idle was at about 100 to 200 rpm, what do you think?

[95LS400Bob]

I am getting P0420 and 0430 codes which points to the cat or the rear sensor on Bank 1.  If it were an upstream leak I would think that the 1st ox sensor would pick it up.  I replaced both front sensors already as that was a cheaper way to determine if those which fail first could be causing the problem.  I'll take it to the smog test station saturday after deleting the check engine light and see what happens.  If I pass I will be really stumped....

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Yeah get rid of the code it should pass with no prob my 1990 did something like that. But now I think I'am having the ECU problem my 1990 LS400 will not idle at all it did have a high idle about two months ago then it started to get lower and lower until the idle was at about 100 to 200 rpm, what do you think?

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That sounds like idle air control valve problem to me. Does it have fast idle when started up cold?

[srgilbert]

Well _ just passed emissions testing HC .014 grams, CO .013 grams. In my state they do not have a standard on CO2 or NOx however CO2 was 79,900 grams and NOx was .019 grams.

DOes anyone know if the ECM will set a check engine light with the CO2 or NOx levels as they are even though my state will not fail me?

This is quite the mystery. The car runs just fine.

[chubyball]

I heard someone in here had a similar problem with yours, the problem was when the car get to the stop the idle get lower than 500rpm and die, another one had a problem with getting off ramp and engine stall after that. I remmemberred they had to replace the ECU to solve there problem.

[srgilbert]

idle is just fine - it's just the p0136 and p0420 codes.