Found out why P0420, P0430

To update my previous thread, (http://www.tacomaworld.com/forum/2nd-gen-tacomas/293193-no-cel-key.html) tonight I found out why I was getting catalyst inefficiency codes for both banks. Dont really know how this happened but wow. Dont know if they were self destructing or someone tried to hollow them out or something, idk. The passenger rear cat only has 1/3rd the flow it should due to catalyst material being caked up at the beginning of the catalyst and a hole through the whole converter front to rear. This would also explain why my muffler sounds like it has a bunch of trash in it, its catalyst pieces!

At least I'm taking care of it now. Parts include:
Magnaflow 49341 OEM grade direct fit manifold
Magnaflow 49342 OEM grade direct fit manifold
2x Magnaflow 51205 OEM grade universal fit converters
Assorted OEM gaskets
Also have a new take off OEM muffler to go on as well

The manifolds seem to be constructed very well and I like the collector they came up with. Fit is excellent with only minor trimming needed for the driver side support bracket to mount up. The y pipe flanges are not tapped so nuts and bolts are needed to attach the y pipe. Hopefully this set up will keep the CEL off.

 

More pics

 

You're the first person that I have ever seen get those. I know they aren't cheap. They look much much nicer than OEM. If it clears your CEL, then that is a major plus. Let us know if it does. Either way, with the better flow design, and unclogged cats, your truck will feel much more responsive.

 

Something overheated the hell out of that cat.
Are you running lean?

 

It might have been a bit lean. I usually get 18-20 mpg mostly town. Tailpipe is also clean, no soot. I drive pretty easy. They were not cheap but Amazon has a good price on them from what I have seen and it saved a good bit over Toyota ones, so I thought I would give it a shot. The driver rear cat started to rattle very loudly so that got me motivated to finally get it done.

 

Did you buy this truck new or used? Perhaps the previous owner drove it differently, towed something heavier than the max tow rating of the truck for too long, or up a steep grade etc... Just guessing. My 2010 tailpipe is mysteriously really clean as well, almost every 2nd gen V6 I see has a really sooty exhaust tip, almost like a Pre-DPF diesel.

Let us know how this baby runs after you get it sorted out. Has your mpg's mproved as well? Seams like this would be a great mod to combine with the TRD cat back or a an aftermarket kit. Best of luck.

 

Do you have any air-intake mods?

 

A miss fire will do in a cat in pretty short order or an overly rich mix. The over use of fuel additives and silicone sealant on intake parts also can trash cats.

 

I have only had this truck a year now so no clue as to what previous owner did. I will say one thing I liked about it was there was no evidence of it ever having a hitch or ball mounted to it when I looked at it. I have no reason to believe it's had a misfire while I have owned it because it's always ran good and the only codes it threw were for the cats. There are a couple coil packs that look a lot newer than the rest so maybe that has something to do with it, idk. Otherwise the truck is stock except appearance stuff and that's the way I want to keep it. Hopefully the weather holds out so I can grab some hardware to throw the y pipe back on and go get the new rear cats put on today.

 

Rear "cats" are actually hollow. In the space between the inlet and outlet of it.

 

I understand the rears are hollow in the center but both catalyst had holes in them. Well I got some hardware and took out as much of the loose material out of the y pipe As I could and bolted it up. Again the fitment is excellent. Drove like a different truck to the exhaust shop. Engine is much more responsive and low end power increased. Waiting now for the muffler and rear cats to be finished up and then I'll see what the difference is in the higher rpm range.

 

Out of curiosity, does she consume any oil?

 

Consumes no oil

 

Those cats look similar to what Toyota MR2 Spyder owners call Pre-Cat Death Syndrome. However, in our little Spyders, one of the key ingredients is the onset of oil consumption due to poor oil control ring design and aggressive tuning for max fuel efficiency in the VVTi tuning. Engine starts consuming oil, O2 sensors cry foul, ECU adjusts ignition and fuel trim, excessive fuel and ignition overheat cat, plugged cat leads to excessive back pressure which starts the cycle all over again... We usually recommend new owners to knock out the Pre-Cat matrix just as a precautionary measure. Here in California, many de catted manifolds are still passing smog, barely, but none the less they are passing.

Regardless of the current issues you are having, messing with the Federal emissions equipment(including the CEL, especially the CEL) is a big NONO! You should have that small dealer by the balls right now!

 

What year is that thing, and how many miles? Any other check engine codes? I hope your not burning coolant... you know what that means... head gaskets. thats what it meant for me and my 05 taco. my cats were completely blown out on both sides too

 

I can only guess that since there are a couple newer looking coils that the previous owner drove for sometime with it missing. All I can say is it does not consume oil, does not smoke, I get good gas mileage, and it does not get hot. I will be keeping a close eye on the new exhaust components in case there is an issue with the engine.
Well just got home from the exhaust shop and wow, this truck has never run so smooth or strong for me ever. Throttle response is much better, low end torque is awesome, and when going up slight hills it does not slow down anymore. Excited its running good. Ill hook the laptop up to it later tonight or tomorrow to see what everything looks like and keep yall posted.

 

2005 with 130k now. No other check engine codes. Coolant is bright pink and oil never shows evidence of coolant in it. I need to check the plugs sometime soon to be sure

 

If you happen to have a boroscope laying around... An inspection of the pistons/combustion chamber would be on my to do list. Add a leak down test and a carbon test of the cooling system and I would probably have all the info I needed on the health of that little bugger. Having plugged up main cats is not a good thing for compression and piston rings in general. I may be blowing things out of proportion here but previous experience guides my thoughts with this as you have no knowledge of just how long it was driven with that little pesky CEL covered or ignored...

 

Good advice Anderson. I will be looking into that

 

I've seen O2 sensors that are in the process of going bad destroy a CAT before but not really like that. I would make sure you have good ones so your new set-up lasts awhile...