Catalyst Monitor Drive Cycle + Catalytic Converter

Hello,

I recently purchased a 2000 tundra and am having a hard time to get a smog test. No related error codes showing up and the catalyst and evap monitor won't get ready (even after driving for a while). Took to the dealership and they couldn't run the cycle either and told me I need new cats. Before buying new cats, I'm just wondering if there's a way to either really determined that they are bad and/or if it's worth to clean them. Below are some deeper details:

1- Cats Performance: Dealership performed an oxygen storage test to both catalytic converters and confirmed both are not storing oxygen. Not sure if I really trust these guys because I initially took there, so they could run the drive cycle (hard to run the cycles on SoCal highways), and when they first called me to give me an update, they said: ".. your truck is being stubborn and won't run the cycles, but we will keep trying.." I'm just wondering if they were trying to get rid of me and didn't want to continue to try to run the cycle.

2- Codes: No codes are showing up regarding this issue. My mechanic friend said that I won't get a faulty cat's code until the drive cycle is complete. A few people told me to keep driving until it runs the cycle, but I'm tired of doing this, specially because I don't have license plates at the moment. The only code that showed up twice is P1126, which the first time that showed up, I was parked slightly on downhill. After putting some coolant (noticed that the level was somewhat low) the code disappeared. I also cleaned the MAF and throttle body. Second time it showed up after receiving the car form the dealership (that's just great, isn't?!), which I was so frustrated that my drive cycle monitor didn't run, that I just cleared the code to avoid more frustration. This code hasn't showed up since then.

3- Cats Cleaning: Is it worth it? I did the CataClean thing but it didn't help. I'm wondering if I should go to either of these routes: 1 Gallon of Lacquer Thinner to a half full gas tank and/or removing the cats and let it sit overnight on soupy water? Any thoughts?

4- O2 Sensors: Dealership said they are working properly. I had my mechanic friend use his live scan tool, and he said they look "ok" to him. I'm attaching the video that I recoded from when we were looking at the live data.



Conclusion, my truck doesn't have any license plates at the moment, so I would rather take action instead of keep driving until something happens (finally drive cycles runs and/or an engine light comes up for a bad cat or something). It seems to me, I probably should just replace the cats but wondering if any of you have any insights/opinion about that?

Any help would be greatly appreciate it.

Thanks!

 

Welcome to the forum. I don't know anything about the drive codes and what makes them fail to run/complete. I have heard of people having success and not with the lacquer thinner. I worry about what it would do to fuel injector o-rings and such. I have used Sea Foam spray in the intake, and SF liquid in the gas, and I would recommend it. Anything is worth a try before spending 3-5K on cats.

https://shop.advanceautoparts.com/p...mbo-pack-sf-ss/11994836-P?searchTerm=Sea+Foam

https://www.youtube.com/watch?v=agAWXnT4-EQ

 

The drive cycle can be completed with the rear axle on jack stands and the front wheels chocked to prevent the vehicle from falling off with sudden acceleration.

I asked a similar question years back on TS. I'll see if I can link the thread with the TSB detailing the many cycles in detail.

 

@Jack McCarthy Thanks! But I have done a lot of driving and even the dealership couldn't perform the drive cycle, so I'm thinking I should try to fix something before just simply drive it to run the cycle.

 

This may or may not be helpful. I have TSB attachments in post #9.

 

Oh, that sux. Well, maybe I can't be of more help.

 

haha I already saw your post a while ago, when I was initially trying to make this work. So, you have been helpful quite a bit, even before replying to my post. Thanks a lot!

 

The Seafoam is for cleaning up gunk in the engine -- that's what the Project Farm video is about (he has sticking lifters and carbon buildup). That will do nothing to clean your cats -- in fact releasing buildup in the engine could theoretically make the cats worse.

 

Whats are your thoughts about cleaning the cats? Thanks!

 

Ive seen the chemicals, but never heard of anyone trying to clean the cats. If they’re clogged, replace em or gut em. If they’re clogged you could have other problems. If the problem is a cracked manifold or o2 sensor, new cats wont fix the problem.

maybe someone has a link to the FSM and you can read the sensors.

 

I've seen some youtube videos on people removing them and cleaning them out via soaking overnight. It certainly couldn't hurt and would prolong its life.

 

As has been mentioned, there are chemicals that you put in the fuel that claim to clean cats. I have no experience with them. I've also seen claims about removing/cleaning, again no experience with them. My comment was just that cleaning the engine is going to do nothing for the cats.

 

Just thinking through this, if the cats are bad, wouldn't the O2 sensors throw a code?

I'd try almost anything else before spending money on new cats that may or may not fix the problem. Try cat a clean or something like that. Also, check to make sure the engine is heating up to operating temp.

How many miles have you driven trying to get it to cycle?

Last thought, can you get a temporary registration from the DMV?

 

Thanks! I have been told that it only throw a code for a bad cat, once the catalyst monitor is complete. Which I'm trying to figure it out why the drive cycle is not running.

I just got a new scanner that reads the coolant temp and live data. I will make sure I drive enough this weekend and measure the temp. If not reaching close to 180 degrees, I will probably replace the thermostat.

I have drove about 300 miles with no success of completing the drive cycle.

I have initiate the process at DMV, which I can use daily passes to drive around. The truck came from an auction, so that's why there's no license plates yet.

Besides checking the temp (and potentially replacing the thermostat), I will also try to clean the cats and replace the rear o2 sensors and take from there. I will keep you guys updated.

I appreciate everyones help!

 

So……. what happened?

 

I had that same problem with my 2002 tundra.I cleaned all spark plugs,cleaned oxygen censors.?cleaned throttle body replaced old fuel filter and added rislone cat cleaner and drove all week. It passed .I would all those things or as many as you can, if still don’t pass, but walker exhaust cats

 

Regardless if the OP shows back up or not, I would like to leave a few comments which pertains to any of our 1st Gens regarding Readiness monitors.

Question I'd have is if the Check Eng(MIL) light was on even if the code was not related. Point being, the MIL can not be on when attempting to complete Readiness Monitor checks. As for SoCal highway runs, in many ways that can be an issue. Each monitor has it's drive cycle speeds one needs to adhere to and most are best done NOT on highway.

Same as above, Check Eng(MIL) can not be on.

As for the video, one needs to monitor the graph with Eng at operating temps and @ Idle. All the accelerating did was show that the O2 sensors went rich which skewed the reading that needed to be seen.

Below is graph after changing my rear O2's. The black sine wave is the front A/F sensor showing reading went from approx .8 rich to .1 lean vdc, which is normal. The red straight line is the rear O2 sensor showing approx .175 vdc, all normal.



I have also attached a 2000 Tundra Readiness Monitor in case OP comes back after 3 months. These monitors are picky and one has to adhere to the drive cycle speeds, loosen gas cap for EVAP, proper temps for ECT and IAT and a number of other criteria or they want run.

 

This is all useful to me. Thanks @MarcioF, I’d still be interested to hear what happened OP….
I need to pass a smog test for my registration this year, which is up next month. I haven’t had any codes come up, nor the CEL, but catalyst monitor has not completed. It is the most difficult drive cycle to complete. There are several preconditions to be met, as well as several steps to the process, all without shutting off the ignition as that ends the test. Then a cold soak is needed before another attempt.
Because of how specific and complicated this particular test is, it’s not uncommon to drive hundreds of miles over a couple or few months without effectively completing the cycle. Most drive cycles pass themselves with normal driving conditions.
A couple points I’d add for others dealing with these or similar issues:
-NOT COMPLETE, or MONITOR NOT READY, means that the system has not been tested. It is not a FAIL.
-(this may or may not be CA specific) Our trucks are not required to complete the evap test, so if the evap readiness monitor status is incomplete, and you are able to complete and pass everything else, that is a PASS. Any test station that tells you otherwise, is in the process of trying to rip you off.

 

While I will agree Catalyst and EVAP are the 2 that require more time than the others, IMHO it's not that they are difficult or complicated, it's because their criteria has to be met, no ifs and's or but's. The reasons a Catalyst would be difficult is that ones Temps are not maintaining >175 thru out the drive cycle process due to thermostat issue or an rear O2 sensor is being lazy. Back when I was first learning Readiness Monitors, most if not all the issues across the net related to Catalyst Monitor was reported to be thermostats not maintaining >175, lazy O2 sensor or a pending code being present.

Since @Darkness is a left coast kind of guy where succesful smog tests are required, I'd suggest adding his suggestion during drive cycle to help with Catalyst Monitor. Putting a load should help in keeping Temps above >175 degree.

2000 Toyota Tundra V8 Catalyst Monitor Incomplete | Toyota Tundra Forum (tundras.com)

 

On my scanner I see my temp gets up well above 175 and maintains. I believe my temps are around 190-195, or 200-205 on the freeway. I’ll double check that today. It’s mostly all the stop signs, signals and humans that make it difficult. To maintain any constant speed for 10 straight minutes round here is difficult in itself. Didn’t think to cruise in 2nd.
Just want to add that I haven’t actually put effort into completing this yet, just reading up on it since it’s the only one that didn’t become ‘ready’ on its own

 

Well…. 1st actual attempt…. NAILED IT!



Doin this late at night with few other cars on the roads was helpful.