P0104 Error On 2004 Ls430

[curiousB]

Well got new catalytic converter installed today. Was more work than it should have been. Rusted bolts. Tight quarters. Oh yeah, I was lusting for a lift again.....

The new converter came with gaskets but they didn't fit well in the milled slots and the Lexus gaskets didn't fit either. Chalk one up for OEM parts. I went after market here and it had its challenges. The Lexus converter was $1300 list and I got one on Ebay for $175.

Eventually got it in but still a leak on flange joint on exit side of converter. Direct fit isn't quite as advertised. Tried Lexus gasket then switched to one that came with converter. Still leaks and at this point I was fed up with crawling around the ground anymore so just left it with a slight leak for now.

Went for a test drive and warmed up the system. Slightly louder due to leak but its a minor leak.

Put on OBDII reader with laptop and went for a test drive with O2 sensors in graphs. Clearly my post converter O2 is a lot more stable with the new converter. Still it bounces around more than the bank 1. I reset the P0430 code so we'll see if it comes back in another day.

I'll put some fresh eyes on the flange tomorrow or Sunday to see if I can get it better aligned so gasket does its job. Failing that I'll take it to a muffler shop where they can maybe bend the pipe a little or weld in a new flange on the pipe side.

The old converter has no visible signs of failure. The honeycomb is intact and all the little holes are clear. I was expecting some visible damage but none found. The O2 test seems to clearly state the new converter performs better. I guess I'll see if I get several days without throwing a P0430.

I didn't know these converters wore out so I wonder if mine got contaminated somehow. Equally confusing is that only one bank got damaged.

The mystery continues but some forward motion. Once I get a better gasket and improved flange alignment and I will be happier.

[landar]

Good to hear you have her back together even with the little leak. Couple of thoughts here(ie: my 2 cents which is worth every penny!). You might not notice anything wrong with the old cat via inspection but the honeycomb is coated with precious(read expen$ive) metals to burn any unspent fuel. You 'might' consider attempting to clean the old cat like the video suggests. And the new non-OEM might be cheaper because they what....scrimped on precious metals maybe? Naw. :whistles:

As to what caused the fairly early demise of your cat with just over 100k miles...you made me a big believer in Premium fuel.

[curiousB]

The plot thickens. Was able to get the flange fixed by tapering the gasket with a grinder and reinstalling. That fixed the flange leak. Then noticed a slight leak in pipe after the O2 sensor. Its under the shield around the pipe so will see if I can get some type of clamp to go over and seal that off.

The bad news is it threw a P0430 code so now I'll not sure what's going on. New catalytic converter, new O2 sensor b4 converter.

I went for a long drive to see if bank 2 converter was glowing red (due to too rich fuel). It wasn't. I then used i/r thermoprobe and bank2 wasn't any hotter than bank 1.

Since I'm at 105k miles I've ordered new plugs but not too hopeful it will help much.

The mystery continues.

[landar]

You can't swap cats from side to side, can you? I guess even if you could, it would probably be a royal pain.

[curiousB]

They are the same P/N buts its no fun working under there. I'd have to buy another $35 in gaskets and lock nuts & bolts.

I'm wondering of the ECU has a measurement issue (noise in ground, amplifier or A/D converter). Maybe I can put an oscilloscope on the O2 sensor outputs and see if it matches the OBDII output (which comes from the ECU). I guess I could maybe spoof the system and wire jumpers from O2 bank2 to bank 1 and vice versa and see if problem moves to other side.

Maybe I'll just space the O2 sensor out with one of these.... http://cgi.ebay.com/ebaymotors/Oxygen-sensor-extender-spacer-HHO-Test-Pipe-O2-2-_W0QQcmdZViewItemQQhashZitem27bd00d6e5QQitemZ170674673381QQptZRaceQ5fCarQ5fParts

[curiousB]

My P0430 code saga continues.

I replaced the Catalytic Converter with one from eBay for $175. Seemed to improve the secondary O2 signal a little but still popped P0430 codes.

Just checked the under hood label and see the OE CATs are California compliant. Maybe this explains why the cheaper 49 state CAT doesn't do its job and maybe why the OEM CATs are $1,000 per. Also the algorithm in the ECU to determine P0430 is maybe expecting a California compliant CAT.

I have a couple of pinhole leaks a few inches past the second O2 sensor where the pipe has corroded. Tried patching them with muffler band-aid but that was a laughable experiment. Since this Y pipe also has the third CAT it is expensive for OE version >$1,100.... Maybe I'll take it to a muffler shop and have them weld some patches on the holes if the pipe is sound otherwise.

Have been experimenting with spacing the secondary O2 sensor with spacers.

http://www.clublexus.com/forums/ls430/580075-p0104-then-a-p0430-two-days-later.html

I expect this will stop the P0430 codes but will maybe kick out a new error.

[curiousB]

Update. In the end it was just a leaky pipe. See thread below for more detail.

http://us.lexusownersclub.com/forums/index.php?showtopic=70886

[curiousB]

"You need a Bank2 (passenger side) catalytic converter. Stop swapping parts, you're wasting time. I've seen it a hundred times. I don't have the luxury of "trying" different things to see what works. I have to be right the first time and, I now know I am also correct. Check aftermarket suppliers for a replacement cat/conv($400-$600). I used one on the last one I did a couple of weeks ago and it worked pretty well. Not as efficient as OE when watching on data stream, but enough to keep the light off and work." Sound familiar?

Well in the final analysis your advice was simply wrong. It was a leak. No parts required. Just weld up the cracked pipe after the secondary O2 sensor. I hope you didn't install 100 unnecessary catalytic converters for folks.

[jaswood]

My P0430 code saga continues.

I replaced the Catalytic Converter with one from eBay for $175. Seemed to improve the secondary O2 signal a little but still popped P0430 codes.

Just checked the under hood label and see the OE CATs are California compliant. Maybe this explains why the cheaper 49 state CAT doesn't do its job and maybe why the OEM CATs are $1,000 per. Also the algorithm in the ECU to determine P0430 is maybe expecting a California compliant CAT.

I have a couple of pinhole leaks a few inches past the second O2 sensor where the pipe has corroded. Tried patching them with muffler band-aid but that was a laughable experiment. Since this Y pipe also has the third CAT it is expensive for OE version >$1,100.... Maybe I'll take it to a muffler shop and have them weld some patches on the holes if the pipe is sound otherwise.

Have been experimenting with spacing the secondary O2 sensor with spacers.

http://www.clublexus.com/forums/ls430/580075-p0104-then-a-p0430-two-days-later.html

I expect this will stop the P0430 codes but will maybe kick out a new error.

The only difference between California and "non-" is that the "non" will not pass visual inspection.

[landar]

Thanks for the update, curiousB. Armed with this information, I am going to crawl under my car before the snow flies and check this clamp/shield arrangement and take corrective action. It could save some heart ache/head scratchin'/money later on.

[curiousB]

Thanks for the update, curiousB. Armed with this information, I am going to crawl under my car before the snow flies and check this clamp/shield arrangement and take corrective action. It could save some heart ache/head scratchin'/money later on.

Take a look at the other thread where I posted photos. You can see the corrosion right under the clamps. You'll have to loosen them (or cut them off as they are probably rusted badly) to see what is going on... Plumbers SST gear clamps are a good (and inexpensive) substitute.

http://us.lexusownersclub.com/forums/index.php?showtopic=70886