Tacoma 06 p0430 and 420 codes

Hi all. I been owning my Tacoma and since I first got it I found out that it had 2 codes popping up. 420 and 430. I replaced both catalytic converters for the codes. Time went by until my next inspection check and it fails for those 2 codes again. I replace the 430 code since the 420 somehow disappeared. Now its that time again to get an inspection and the 420 code is back. I am tired of replacing my catalytic converters. It is pricey and it has made me see this truck as a burden. Can anyone please help me figure out what the root of the issue could be? What could be causing my converters to fail?

 

Improper fuel mixture can kill cats quick, if you have a scanner it would be worthwhile to see what your long and short term fuel trims are. If they are out of whack that would point to an issue that could be hurting your cats. I would imagine you'd start seeing other codes too though but maybe not

If you're replacing OEM cats with cheap aftermarket ones, they don't tend to last that long...cheap cats have less of the material inside that filters the emissions, and you'll see those codes again sooner...especially if the truck isn't running as well as it should and dumping too much fuel through them

 

What do you mean by fuel trims? Also no other codes have ever popped up its been those same two. And I have only used original parts. But they went out in less than a year.

 

Your ECU monitors your truck's short and long term fuel trims, which you can see via an OBDII scan tool like what shops use to read your check engine light codes. There are a lot of ways to do this, cheapest is to get an OBDII plug-in on Amazon for ~$20 and connect to it with the Torque app on your phone.

Or you can buy an Ultragauge or Scangauge to plug into the OBDII port. All of these will show you your fuel trims

Generally you want your fuel trims anywhere between -10% and 10%...anything higher than 10 indicates you're running too lean, anything lower than -10 means you're running too rich. Depending on what you find you can start to know where to look next

Without a scan tool though you really have no way of knowing what they are

 

So I know this may sound like a pain in the ass, but it's something I would have begun doing in CA had I not moved:

I was gonna buy a set of new cats and only put them on when I needed a smog check. The work would be a bitch every year but it would help me not have to worry about them going bad. I know that's more than likely the answer you're totally not looking for but it was my plan when my cats died at 80k. Wishing you the best!

 

OEM cats dying early is definitely not normal and should be looked at as an indication that the truck is not running right. Aftermarket cats the same applies, but they are more likely to die quicker because they aren't made of the same quality.

 

I'll go head and buy one from Amazon..see if my trim levels are off. So any Amazon OBDII has the trim level scanner?

 

Yea thing is they were original parts so it doesn't make sense.

 

Amazon sells the little OBDII plug ins like this one

for Android Phones ONLY - Wireless Bluetooth Diagnostic OBD2 Scanner Car Code Reader and Scan Tool for All 1996 & Newer Vehicles ELM327 Compatible OBDII

https://www.amazon.com/BAFX-Products-Wireless-Bluetooth-Diagnostic/dp/B005NLQAHS/ref=sr_1_12?crid=1L1L277XKUU4I&dchild=1&keywords=obd2+scanner&qid=1604446517&s=automotive&sprefix=obd2+%2Cautomotive%2C210&sr=1-12

That plugs into your OBDII port beneath the dash (on my 04 it's near my right knee), then it connects to your phone using Bluetooth or Wifi signal. Have to download an app onto your phone like Torque (there are several apps), and that will allow you to read engine codes, clear codes, read fuel trims, battery voltage, engine and trans temps, intake temps, ignition timing, all kinds of cool stuff.

Or, you can spend a little more and get something like an Ultragauge that plugs into the OBDII port and displays info on a screen for you

UltraGauge EM Plus Automotive OBD2 Scanner, Code Reader, Gauges & Mileage Calculator - All New v1.4

https://www.amazon.com/UltraGauge-A...ultragauge&qid=1604446653&s=automotive&sr=1-1

These are basically watered down versions of what shops use to diagnose issues when you bring your truck in. You can also buy the kinds of scanners they use, but then you're getting into the hundreds of dollars territory

 

Awesome ill go head and buy that tool, see maybe that's the issue. Thank you.

 

I had the 420 code. Turned out to be the gasket connecting the cat to the Y pipe.

You've replaced cats multiple times? You poor (literally and figuratively) bastard. That's not cheap. Find an inexpensive OBD2 scanner on Amazon and get the torque app.

I created a graph gauge for both O2 sensors and bank 1 was allllllll over the place, while bank 2 was nice and smooth. The culprit was a tiny leak as I noticed some soot at the joint.

 

You only had to replace a gasket? Yes and I dont want to replace the cats yet again its a pain

 

That's it. 2 gaskets as you can't separate one side at a time. Used a ratchet strap to pull the Y pipe and the rest of the exhaust back and apart. Not to bad to replace overall.

 

I already ordered the OBDII scanner, I'll be looking into that as a possible solution. Thank you.

 

This may help you out making sense of the data stream regarding P0420/P0430 codes. I thought it was for the Taco, but turns out it's a Jeep.

https://www.youtube.com/watch?v=CflIvd5VOoA

https://www.youtube.com/c/SouthMainAutoRepairAvoca/videos

Best info video's on YouTube....just type in what your looking for on his SEARCH bar.

 

I had the same codes about a year ago - '05 with 155k miles at the time. If you search here P0420 code you'll get plenty of threads and ideas. Rather than replace the cat I tried to step through from least expensive to most. I got lucky. I visually looked for leaks (didn't find any), cleaned the MAF, added fuel cleaner, cleared the codes and was good. If that didn't work, I was going to replace the gasket mentioned above. Then move on to replace the O2 sensors and potentially the cat, but I didn't have to get that far.

 

The second item listed above is NLA on Amazon. Is there a good OBII reader for Gen I Tacoma's that someone can recommend?