mjbtn

Hello,

I'm not a newbie here, but I'm also a mere DIY mechanic (though prowessed enough to tackle such projects as replacing rear air suspension with coils+shocks).

I've got a 2004 ES330 (2nd owner) with roughly 315,000. We didn't pay much for the car in 2012 with 164,000 miles. So, i've never gone overboard in maintenance of it. A year ago, when it was time for emissions testing, I had a persistent P0430 that failed me. Out of desperation to avoid the cost of replacing the front/left CAT, I ran a bottle of Cataclean through, and darn if the code didn't go away and I passed.

The code returned back this past summer at some point. It was originally triggered I think by a misfiring coil pack on #2. I had replaced it with a Denso (twice as the first one failed after a month). The misfire ceased. But I suspect it fouled the front CAT some (and the P0430 made sense). But just before testing this time, I also had a P2241. So I replaced the front/left A/F first. That nixed the P2241, but the P0430 remained. I again ran Cataclean through, but no joy. After a couple of tanks, I repeated the Cataclean. Again no joy.

So I started looking at the CAT being clogged. But, no tell-tale signs of it save for reduced mileage. Good power and acceleration at high speed still. Idles very smoothly. Also, good puffing exhaust at the rear (though I know this isn't definitive since the two banks merge post-CATs). So, I decided to replace the Bank 2 downstream O2 (again a Denso).

While I had the old one out, I decided to stick my handy new Teslong borescope into the downstream port. I've attached some pics of the tail end of the Bank 2 CAT. Definitely shows some deposit at the lower end of the substrate. But it is white, so I suspect phosphorous and/or ash. But I also decided to look the other direction, and there was white debris trailing down the bottom of the pipe. I know substrate could be crumbling out. But it was a very windy day, and as I was scoping it, wind was whipping all around me and into the pipe. The debris blew around like styrofoam beads. Ie, it was *very* light material. It almost looked like the white debris on the ends of the lower substrate getting blown out of the CAT. Which makes me wonder if the Catacleans did have some positive effect in dislodging some of the build up.

So, after installing the new downstream Bank 2 O2, I went for an hour's drive out on the Interstate at 80mph. The P0430 didn't clear, but now I'm showing a pending P0420. I can see the Bank 2 CAT being fouled by the misfire (and/or the P2241 issue), but now both banks?? I've still got to check items like EGR, PCV, cracks in intake or exhaust, and even the gas cap (it's original). Seeing both codes, though, now has me suspecting something else might be going on upstream of the CATs. The car is old, and very high miles, and we've gotten our money's worth out of it. But it drives and runs nice still. I hate to think of replacing both CATs on a vehicle this old though. And, while I don't doubt the downstream O2s are reading right (especially since newest Denso on Bank 2 is reading identical to the one it replaced), I wonder if there is some other avenue(s) that I might consider before deciding whether to replace them or the car itself.

What REALLY bites is that the state of Tennessee voted to end mandatory emissions testing around Nashville back on July 1st of 2018. Yet, due to EPA red tape, yadda yadda yadda, the testing requirement won't end for another 2.5 years. I don't think I can successfully dodge tag renewal that long! I've read that taking the CATs off and soaking them in a solution of citric acid or Dawn detergent can have a positive effect on efficiency, maybe enough to get passed for emissions. But that is still a lot of work to get at the rear bank and what not.

From what all I've described, along with the scope photos, what would some of you suggest before making the really painful, yet ever looming closer conclusion that in fact one or both CATs are beyond salvation?

Thanks!!

Mark


It appears that at least part of the substrate's channels are not collapsed. I could've open the upstream sensor port of put a bright light in to make a better determination.

This looks like ash build up to me, but I'm NOT a trained mechanic with emissions expertise. Hopefully some of you are!

This must be the same white material from the bottom side of the substrate. It is light weight too. The wind blew this stuff around like styrofoam beads. This also make the think it is an ash of some sort. I would think that crumbing substrate would be more weighted down with metal oxides.

Using OBD Auto Doctor (paid version), I captured some plots of the upstream and downstream sensors while on the Interstate drive. Here I had slowed down for a cop helping a stalled motorist. Then I resumed the cruise.

Yet another plot while holding 80mph under cruise. The downstreams are calmer, but still look more jagged that I would think they should be.

yeskay

have you tried CRC05063 .

Oro

Install spark plug non-foulers.on the downstream 02 sensors.

ArmyofOne

^This. Make sure they are the 90 deg angled ones.

mjbtn

Any particular reason why the 90deg ones? And, how likely are they to be detected by visual inspection by an emissions tester with boom extended mirror?

mjbtn

Yes, in between the CataCleans. I didn't appear to make any difference.

crwys

if you buy the straight the ones they will be too long to fit (I know this from experience) where i had my smog done they didnt look underneath the car the check for modifications so maybe it just depends.

Richardsr

Nad1370

Yep...your cats starting or already are deteriorating at levels that exceeds malfunction threshold.
Following up Richard's response, if the catalyst is failing, the O2 sensor waveform will alternate frequently between RICH and LEAN.

Dont bother looking for an EGR problem, your car doesnt have one.

FWIW, my 1MZ is ticking at 341k miles on orig cats.
I do maintain it religiously so maybe thats helping it prolong the life.