2009 GX470 O2 sensor/catalytic converter question (1 Viewer)

[HomersCanyonero]

My fix for the frequent and constant codes P0420 and P0430 were the cats. I replaced both integrated cats with Lexus oem cats (under $1000/pair including taxes and shipping) and the codes went away. It's been a year that I'm code free.

Prior to replacing the cats, I tried a few tricks....
1. Went to a handful of muffler shops, repair shops, etc. and they all said it was the cats, but I didn't trust them!
2. Bought the iPhone Car Scanner app and wifi odb2 connecor to read and clear the codes
3. Replaced all O2 sensors myself. Bought a O2 socket wrench at Harbor Freight.

Finally, I bought the Lexus oem integrated cats for under $1000/pair including tax and shipping. Bought online from a Toyota/Lexus dealer. Paid $200/total in labor to get them installed by a local repair shop.

I kept the old cats. I should sell them to a metals recycling place. I heard they give top dollar for the metals in the cats.

 

[Rednexus]

I kept the old cats. I should sell them to a metals recycling place. I heard they give top dollar for the metals in the cats.

I sold both of mine for $585 when upgrading to long-tube headers. Definitely unload them!

I've never actually had a vehicle with bad cats that stopped working for no reason, although one vehicle killed a cat due to a burnt valve, caused by a bad injector, causing lots of unburnt fuel to go out the exhaust (which killed the cat), but I was able to fix that with the simple defouler trick (after having a valve job done). Otherwise, it's always been sensor related for me.

 

[HomersCanyonero]

I sold both of mine for $585 when upgrading to long-tube headers. Definitely unload them!

I've never actually had a vehicle with bad cats that stopped working for no reason, although one vehicle killed a cat due to a burnt valve, caused by a bad injector, causing lots of unburnt fuel to go out the exhaust (which killed the cat), but I was able to fix that with the simple defouler trick (after having a valve job done). Otherwise, it's always been sensor related for me.

How did you find the place that buys used cats for metals?

 

[Rednexus]

How did you find the place that buys used cats for metals?

I did a rather extensive Google search for metals recyclers, and then combed their websites and made calls to verify that they bought cats. One place was in a pretty rough part of town so I didn't even get out of the car as I had my son with me, but then I found another place out in the sticks that bought them and they paid me cash.

Those were the only two legit buyers I could find in the St. Louis area. I'm sure you'll have several buyers in SoCal due to it being a much larger metropolitan area.

 

[jiggletits]

All you folks replacing cats... were your headers leaking prior to the cats failing? That is usually what causes it in my experience on other vehicles.

My passenger manifold has a very light tick on cold starts, I'm doing short tube headers real soon so I don't cook the cats.

As I understand, a leak before the cat can mess up o2 readings and cause a rich fueling situation that leads to the cats burning up as well as worse MPGs than usual.

 

[HomersCanyonero]

Headers not leaking. Not sure why mine went bad, but I’m not the original owner.

It’s not common to have problems with the cats but I had a persistent p0420 and p0430

 

[IHTFP08]

I just replaced all 4 O2 sensors, cleared codes, did the drive cycle, codes came back. Looking at aftermarket exhaust options now vs spending $3k on OEM replacements. Also have a slight exhaust tick too.

 

[IHTFP08]

Does anyone have any experience with the DT shorty headers, universal 2.5" cats attached to stock exhaust? Seems like buying headers, cats and having a shop weld some flanges onto the headers/cats so they retain the stock O2 sensors and locations is a better/less expensive setup than OE replacement manifolds/cats. I still need the 02 sensors for an ECU check/"visual inspection" for emissions in my county in GA.

 

[eL PeReZ eSe]

Does anyone have any experience with the DT shorty headers, universal 2.5" cats attached to stock exhaust? Seems like buying headers, cats and having a shop weld some flanges onto the headers/cats so they retain the stock O2 sensors and locations is a better/less expensive setup than OE replacement manifolds/cats. I still need the 02 sensors for an ECU check/"visual inspection" for emissions in my county in GA.

Do a quick search. a couple of threads and info on DT short headers in here.

 

[Rednexus]

The exhaust leaks might be causing it, as mentioned above, or the O2 sensors were a bit off and slowly killed the cats. the DT headers will be a good upgrade, and universal cats aren't terrible expensive. The shop will need to be able to do some fabricating to mate the DT headers to your new cats and the downpipe that leads to your Y pipe. Being that the headers and the cats will all be stainless, this should really be done by an experienced TIG welder (which a good exhaust shop should have). Luckily we don't have emissions here so I was able to use the LT DT headers.

Also the header install on it's own is pretty difficult and is easily a 7-10 hour job for a shop, plus the fabrication time that they'll need to add new cats. But, you'll end up with a better product that will give your GX more power and should never crack again.

 

[IHTFP08]

I ended up buy buying two of these: O2 Simulator Mini Cat Cel Fix stainless steel Rear O2 sensor simulator. - http://www.bigdaddiesgarage.com/mini-cat-cel-fix.html, for the rear 02 sensors. Codes gone, and OBDwiz says I'm ready for emissions. I think I'm going to keep the manifold cats deleted and keep using the cheaters on the rear sensors. I think ST headers will be the best fit, keeps the factory 02 sensor locations, and I could get a resonator or something that looks like a cat welded in place, but I've never had anyone visually check like they're supposed to.

 

[Rednexus]

FYI, I'm running similar O2 spacers with long tube headers and deleted upstream cats, and get zero codes. If you're willing to roll the dice on the inspection....you can consider long-tubes instead. They provide more power and the install is much easier (no welding and there is more room to get at the manifold bolts, although it's still a PITA). I have the rear cats still installed on the midpipe with my setup, so it's not totally de-catted. Others have welded in additional cats on the Y-pipe or catback as well.

 

[IHTFP08]

FYI, I'm running similar O2 spacers with long tube headers and deleted upstream cats, and get zero codes. If you're willing to roll the dice on the inspection....you can consider long-tubes instead. They provide more power and the install is much easier (no welding and there is more room to get at the manifold bolts, although it's still a PITA). I have the rear cats still installed on the midpipe with my setup, so it's not totally de-catted. Others have welded in additional cats on the Y-pipe or catback as well.

Thanks. For the LTs, they come with an upstream harness extender, assuming it gets relocated to the collector or just afterwards. Is there room to install the downstream o2 sensors while keeping the same wiring location? or do the downstream need to be extended too?

 

[vipergrhd]

My fix for the frequent and constant codes P0420 and P0430 were the cats. I replaced both integrated cats with Lexus oem cats (under $1000/pair including taxes and shipping) and the codes went away. It's been a year that I'm code free.

Prior to replacing the cats, I tried a few tricks....
1. Went to a handful of muffler shops, repair shops, etc. and they all said it was the cats, but I didn't trust them!
2. Bought the iPhone Car Scanner app and wifi odb2 connecor to read and clear the codes
3. Replaced all O2 sensors myself. Bought a O2 socket wrench at Harbor Freight.

Finally, I bought the Lexus oem integrated cats for under $1000/pair including tax and shipping. Bought online from a Toyota/Lexus dealer. Paid $200/total in labor to get them installed by a local repair shop.

I kept the old cats. I should sell them to a metals recycling place. I heard they give top dollar for the metals in the cats.

I get the $1k parts but how did you get someone to install both manifolds for $200 in SoCal? You are still in Socal right? I need mine replaced too.

 

[Rednexus]

Thanks. For the LTs, they come with an upstream harness extender, assuming it gets relocated to the collector or just afterwards. Is there room to install the downstream o2 sensors while keeping the same wiring location? or do the downstream need to be extended too?

Downstream sensors are located in the midpipe, past the headers, and do not need to be relocated.

 

[IHTFP08]

Downstream sensors are located in the midpipe, past the headers, and do not need to be relocated.

I appreciate it. Now off to find some LTs instock somewhere.

 

[HomersCanyonero]

I get the $1k parts but how did you get someone to install both manifolds for $200 in SoCal? You are still in Socal right? I need mine replaced too.

Found an independent mom & pop repair shop in Arcadia. I left my suv there one morning and got it back the next night.

Also, I checked with a couple other independent small auto repair shops and i remember getting quotes for $300 just labor for the pair. This was in 2021 prior to the current craziness that’s going on.

Try a muffler shop. I asked around to get an idea if I could bring my own parts and how much to install. I stop in person and ask how much to install the integrated cats on the GX470 and they would tell me.

I did the same back in 2018 for the radiator, hoses, thermostat, cap, timing belt, water pump, drive belt, idler, coolant, etc. I show up with all my parts and ask how much for labor. I got 4 quotes between $500 to $900 to basically install all new cooling system.

Some places would say they don’t deal with customers who bring their parts. One shop said he only takes quality parts like denso, aisin, etc. Not the crap aftermarket universal parts.

 

[SteveH]

The spark plug anti-fouler mod is famous in the Toyota world for P0420 code fixes. It makes your rear-most O2 sensor less capable, which creates the difference in voltage that the engine computer is looking for. The proverbial $10 fix to the multi-thousand dollar problem.

 

[IHTFP08]

So I got the set of DT LTs from Summit, luckily they were in stock. Are the Burtman Ti studs/nuts a must have/nice to have on the install? Worth the $250 for them?

 

[jiggletits]

I would use OE studs/nuts/gaskets.