Emissions Problem - Failed Smog

Thanks for posting. Based on this article, I'll need to look into rich fuel throwing off an O2 sensor, or a bad O2 sensor making the fuel rich, either of which can be the source of the P0420 code thrown, or actually ruin a cat which also of course throws the same code.
Also, my spark plugs are questionable, and secondary could be sending too much fuel down the chain.

Still not convinced my cat(s) is bad, but I'm getting closer to understanding if they are bad, why they went bad (possibly due to tuning issues in the engine) and correcting the actual problem.

The other interesting thing is that if there are tuning issues with the engine, that would surprise me because it's running well. But I suppose once these things are fixed, then I would notice the improvement...

 

Even if your cats are good without the number you need new cats, thats just how cali works. So even if you pass the system scan if you fail visual then you fail smog

 

I'm wondering if the number is installed facing up towards the floor of the truck, and no one will able to see it, or if this aftermarket unit has a number at all.

 

You mean Kalifornistan?

 

I'm looking at this one right now. Looks to be the iOS version of what you have. Or I could just get a regular non phone related scanner for about the same price, unless the phone scanner has more features.

The app for iphone is called "OBD Fusion," for android is "Torque" like you said.

BAFX Products Wireless WiFi (OBDII) OBD2 Code Reader & Scan Tool/Wireless Check Engine Light Diagnostic Scan Tool for Cars & Trucks/for iOS. iPhone & Android Devices (1)

https://www.amazon.com/BAFX-Product...rd_wg=67bLS&psc=1&refRID=JA08DVTJ07SFETQP1CVT

 

In cali all replacement cats have to have that number on them (if you had a shop do it). So its possible if you got it replaced then smog you will pass, but if for some reason that number was damaged before your next smog you will fail the visual

 

Phone one is easier, lets you just leave the reader pluged in and then you can check when ever vs having to carry around one of the big hand held ones

 

That is the same one I have, but in a more expensive Apple version. I'd recommend a phone based one vs. a dedicated display (in our price range) because it can do more.

 

@2000 Tacoma Black don't forget some basics. Lack of basic PM can be one of your biggest enemies here, and you should do a few things before any further diagnosis to remove them from the equation.

1. Change your plugs using the OEM Densos dual electrode specific for your 5VZFE:

$18 K16TR11 Spark Plugs, Pack of 4

K16TR11. I can't believe you haven't changed you plugs having 140k miles on them, if I read that correctly.
2. Clean that disgusting K&N filter. It has probably polluted everything downstream with gunk and messed up metering and diagnostics.
3. Clean your MAF using MAF cleaner. You need to spray it down inside the tube.
4. Clean your throttle body.

As others recommended, I also like the OBDII reader/Torque app, which I got to sort out a bad A/F sensor forward of one of my cats. That is not an O2 sensor. Mine failed at about 145k miles. Code 1134.That's about their lifespan.



New crush gasket for the throttle body after cleaning. These are not reusable, and you don't want an air leak there.



If you need a new Air/fuels sensor, this is the one mine took, but they are very specific to differetn model tweaks and details. Double check exactly which one you need. I found a dealer on Ebay with a reasonable price. Get OEM Denso.

 

True...I have TRD headers on my truck and even though I have the CARB sticker for them, I nearly didn't pass inspection because the part numbers for the headers state that they are for an '03 Tacoma and not an '04 like mine. The smog tech told me that he'd let me slide but he could technically fail me on that.

I get that we have to have emissions testing in overly populated places like SoCal where the smog would otherwise be horrendous and downright deadly if not for the emissions laws, but little things like that are just plain retarded.

Oddly enough, he didn't say anything about my URD 7th injector kit which is completely against CA smog regulations...it's plain as day to see in the engine bay if you know what it looks like. I was sweating bullets over that lol.

 

At least you see the valuable intent of the laws. So many people just don't get it.

 

x1000 on the BAFX and Torque app.

 

Oh yeah, I completely understand why they exist out here. I've said this before in other emissions related threads, but many people my age take for granted how fortunate we are in this day and age to have the air quality we do out here, compared to what Los Angeles was like back in the 50s and 60s...before smog equipment. My grandparents have photos of the area back then where the smog was so thick everyday that even on a clear and sunny day, you couldn't see the sky or the sun and it seemed like it was completely overcast nearly every day. The mountains that line our horizon were completely obscured by a thick layer of grey smog...nowadays we have a beautiful skyline with snow capped mountains in the winter that we otherwise wouldn't be able to even see, let alone enjoy recreationally. Just look at modern day photos of places like Hong Kong and that's exactly what LA would look like if they hadn't implemented the changes they did back in the 70s.

I'm all for regulating the air quality, I enjoy being able to breathe and having an environment to explore/offroad in that isn't toxic. If anything people shouldn't take it out on the government for mandating emissions equipment...they should take it out on the general population for not using birth control more often lol.

Sorry for the slightly off topic rant...

 

Op I don’t remember what engine you have but i just went under my truck, only the front cat has a number on it whch you can see through a cut out on the heat shield. But then agian even though my truck was made in cali its not a cali version ( i dont have the egr system) so idk if this changes the cats

 

This is great. Thank you for the time you took to do this.

1. I'll definitely change the plugs ASAP, but I should wait until I get the scanner to see what the current situation is. Btw Amazon is saying that the

$18 K16TR11 Spark Plugs, Pack of 4

K16TR11 will not fit my truck, but my user manual says it does
2. I would rather just replace with OEM I think. The reason I don't clean it anymore is that it sucks the oil beads back in and throws a code, and I got tired of dealing with it.
3. Will look into this.
4. Will look into this.

 

Thanks for checking yours and for the pic. Mine looks like this...

 

My code was on the inside up towards the top, kinda hard to find if you dont climb under the truck.

 

I would definitely opt for ditching the K&N for OEM, but was not sure how quickly you need to get this smogged, and how long it might take you to get an OEM intake.

 

x2 on getting rid of the K&N...especially if it's the oiled filter kind. I had all kinds of trouble with that filter messing up my MAF sensor on my previous truck. Also not sure if they're CARB approved or not so that could be an issue if the smog tech sees it.

 

I think k&n are carb legal, if you dont have the sticker you might be able to call k&n and get a new one sent to you. You might also wanna look into getting a dry filter, afe makes them not sure if ut fits k&n but im sure k&n makes dry ones. This way you can you can have all that squared away so yoi can pass smog until you can find a oem one or hust keep it like that