Emissions Problem - Failed Smog

New member...this is my first thread. I have been enjoying reading through this forum, looks like a very informative and fun place.


So, I went to smog my 2000 Tacoma. I got 3 fails:


Catalyst

OBD Bulb Check

OBDII


In addition, they are telling me that there is an engine family code or serial # that is embedded/written on the front cat itself, that they could not read when they looked under the truck. They recommended replacing the cat, or they said if I can read the code myself I can give it to them and they’ll put it into the computer. So that cat is probably ok, but they couldn’t test it. This same shop passed me two years ago despite not being able to read it, so I feel they could do this again if they wanted to. They said the number should look like this: D-xxx-xx

The check engine is on and has been on for some time. They said the code thrown was P0420, and they are saying the rear cat is bad, but I haven’t determined that yet, and this is the big piece of the puzzle. I am trying to find out if I really have to replace either of these cat converters.

They are quoting me $460 OTD for the rear replacement and front cat as well (the illegible code cat), or $280 for the rear cat if I can solve the ‘illegible’ issue myself, or $75 for labor to weld one in if I bring my own rear cat.


So on top of figuring out how to troubleshoot the Catalytic converter, OBD Bulb Check, and OBDII fails, I have to figure out what to do with this front cat that technically hasn’t failed yet. I replaced the front cat 2-4 years ago. I don’t recall ever replacing the rear cat.

The final piece of info is that I have a K&N Filter that aside from the cool swoosh when you hit the gas, has only given me headaches, and I will eventually look into replacing it. Do you think there is any way that it could be affecting this smog fail situation, with confusing the computer with air/fuel mixtures or something else? (I remember when I had to smog last time, part of the problem was I needed a model/unit sticker from K&N.)

I have read through some of the threads on the emissions forum here. Thinking about renting an auto scanner to see any and all codes thrown, and in which order. I figure the shop may not have told me the full story.

Final note - My spark plugs are on about 140,000 miles. I think the ones in there are Bosch platinum 100k -120k can’t remember. Could old plugs be causing this as well?


Thanks for reading and for your insight.


I'll get pics up in just a moment.

 

AIR INTAKE







FRONT CAT (WITH ILLEGIBLE OR LACK OF SERIAL #)

 

REAR CAT

 

What State are you from From trying to get a smog inspection ??

Im from Socal and easily passed smog with a Supercharger , cyl head , header and K&N CAI

 

I'm in So Cal as well.

 

What year is your truck, and maybe it's tuned a little better than mine? Although mine is running really well, maybe the computer codes or sensors are off or something.

 

2002 but has only 66k miles on the odometer , im still running the OEM Cats . Also all the Aftermarket parts have CARB 50 state legal # decal on the firewall

 

I think you have two separate issues. One is the OBDII test cycles have not completed, and for me is a real bitch to complete. After a battery disconnect and 1,700 miles all my sensor test cycles have completed except catalyst (I have no codes or engine light). For about $30 you can buy a cheap scan tool that relays info from the onboard computer to an Android phone to see when the test cycles have completed.

If you Google this you will get better info than I can relay: odbII 2000 tacoma test cycle

As to your codes and cats, someone smarter will come along.

 

If your mil light is on, they won't attempt to smog. In CA 00+ they just plug their on board reader to your vehicle, more dyno like 99 and older.

State law been very strict and is changing yearly. They need to be able to read your aftermarket CARB number and note the system you don't have factory cat like your rear. I doubt your cat are bad.

Go buy a scanner, clear the code and drive until all modules are green and ready.

 

Clear the good. Can you elaborate a bit more?

 

Typo, clear the code. Or you can disconnect your battery cable, but buying a decent scanner is good investment for the long run.

 

Gotcha. I didn’t realize the scanner could clear the codes. I thought it just read them.

Can I also do this with the scanner that I rent at an auto parts store?

 

Until just a few months ago, CA used to allow any one test cycle to be incomplete. I'm told the two hardest are evap and catalyst. Originally I had exactly those two cycles incomplete. My evap is now complete but not my catalyst.

The recent change now states you can only slide on an evap incomplete. All the rest must complete.

CA wants us to ditch and buy hybrids.

 

That statement is not true. 99 or older, they still allow 1 incomplete cycle. 00 and newer, all cycle must ready.

 

Clearing codes will not solve the problem. They'll come back. It'll only fool you into paying for another smog check. Unfortunatley the codes are symptoms of a problem. You have to solve the problem, not clear the code.

 

I don't feel like looking it up again. Post 2000 vehicles only allow the evap to show incomplete. It just changed like six months ago. I'm suffering from the same issue of having a bitch of a time getting my cycles to complete and have researched it to death as well as got the official answers from the California Referee.

 

There's many symptom that can trigger a mil light such as bad gas etc. You clear the code and hope that's the issue.

 

If you're like me, you might want to spend the $30 vs. going to rent one every time you think you may have completed a cycle. It's a handy tool you can use later.

 

My neighbor is a smog tech, he said nothing change. Always been 99 and older, BAR allow 1 not ready module. 00+ all module must be ready.

 

It says right there only the evap is allowed to be incomplete. Thanks for looking it up.

Maybe I was sloppy. What I meant all along was 2000 vehicles and newer, not post 2000. But a model year 2000 was the subject of our discussion.