Hello,
I have a 2006 Daihatsu Sirion ( Same car as Toyota Passo ) I had for about 3-4 months now a CAT_RDY INC under I/M Readiness. NO errors codes or check engine light. Yesterday I realized on top of that I have a O2S_RDY INC.
Car is running fine good acceleration, good top speed. Only thing I have noticed is a bit higher fuel consumption.
The only thing that I did yesterday is take the car for the yearly oil change and since its weekend and I have some free time I did some checks on the car: Fluids, Battery, Tyre pressure etc and when I connected the OBDII I found I have one more I/M Readiness INC.
When I took the car to the mechanic for the oil change I told him I have a CAT_RDY INC and without looking at the car he told that the O2 sensor need replacing. After I took the car back from the mechanic the O2S_RDY INC popped up in OBDII. Coincidence ?
What needs to be done now ? Replace the CAT and O2 sensor ? that's like 1000$ job and recommendations ?
The mechanic I think is trying to scare me by saying if I don't change the O2 Sensors which is about 500$ job it will damage the car resulting the car going into safe in the long run.
I don't perceive the issue being so serious if it was something critical I should be getting error codes which I don't have. Correct ?
You NEVER replace parts just because an I/M Readiness Monitor is showing an "INComplete Status"
I/M means Inspection & Maintenance Readiness.
The I/M Readiness results don't tell you if a sensor or component isn't working. It tells you if the predefined drive cycle(s) necessary to run the self-diagnostic tests have been met and if the individual self-diagnostic test was completed (OK) or not completed (INC).
The computer performs the readiness tests under certain "driving criteria" (and sometimes requires not only a variety of speeds and rpms in one drive cycle, but in two successive drive cycles). The criteria vary upon the sensor/component being tested.
(This entire I/M Readiness system is to comply with pollution/smog inspections. It was created to keep people from Clearing Codes and then trying to get through inspection before the code trips again).
Those "Incompletes" (INC) next to the components just means that the "driving criteria" for the computer to complete the self tests haven't been met since the last time all the codes were cleared.
Whenever codes are cleared (or the battery disconnected) the I/M monitor tests have to start all over to show "OK".
Probably why that O2S_RDY INC popped up after your mechanic had your car. (He probably tried to clear codes).
Some of the "driving parameters" for the computer to perform the individual sensor/component tests are pretty specific and if your driving doesn't match the criteria required, the test won't be ran and an INC will be displayed next to the individual Emission Control Component.
Also, in some cases the catalytic converter monitor will not run until the oxygen sensor monitor has run and completed successfully
One more thing. If the computer finds a problem while performing these tests it will throw a code and your Check Engine Light will be illuminated and you'll be able to hook up your scanner and retrieve the specific DTC (code).
For example, when the computer runs that EGR Monitor test. It uses voltages it recorded in its KAM (Keep Alive Memory).
If the voltages at EGR 0% (EGR valve fully Closed) and EGR 100% (EGR valve fully Open) vary from the values recorded in its KAM, it will throw an EGR code but the I/M EGR readiness result will read OK.
So let's say you're a guy who lives in a small town. You drive 5 miles to work each day and 5 mies home.
On the weekends you drive the other direction 5 miles to the grocery store and 5 miles home.
The bar is 8 miles up the same road.
You girlfriend lives 10 miles away.
You seldom drive at highway speeds for any period of time. You seldom idle for more than a couple of minutes.
Your CAT_RDY I/M status will always show "INC" because that particular test requires a driving cycle something like:
- Minimum 330 seconds since start-up at 70°F
- Engine coolant temperature is between 170°F - 230°F
- Intake air temperature is between 20°F - 180°F
- Time since entering closed-loop is 30 seconds
- Inferred rear HO2S sensor temperature of 900°F
- EGR is between 1% and 12%
- Part throttle, maximum rate of change is 0.2 volts/0.050 sec
- 10 minutes at 55 mph or more
- Followed by 20 minutes between 30 and 45 MPH
- Fuel level is greater than 15%
- Engine RPM 1,000 to 1,600 RPM
- Engine load 15 to 35%
- Inferred catalyst temperature 850°F - 1,200°F
So understand, those I/M Readiness Status results don't mean anything if you don't have vehicle inspections in your state.
I live in a rural area of FL. I had to disconnect my battery a couple of months ago to perform a repair. That reset those I/M tests results.
Like the guy I cited as an example above, I don't drive on any roads where I go 55 mph for 10 minutes or more.
I guarantee my CAT_RDY I/M status is INC. It doesn't matter to me at all because we have no vehicle inspection in FL.
You can try to research "Toyota/Daihatsu I/M Drive Cycle Requirements". Many auto companies publish specific criteria for their individual I/M drive cycle requirements. I've never seen Toyota's. Maybe try to "extrapolate" from other Japanese auto makers
Also, find a better mechanic.
This answer is so complete and so great. Damn.
Also yeah, it’s a Sirion, they pretty much just do not have issues with their exhaust systems. Such a great little car…
Thank you for your time and the long and precise explanation. This is the 3rd mechanic I tried.
A couple of months ago I wanted to do an oil change I took my car to the mechanic and to my amazement he sucked the oil from the top and told me that there was no need to change the oil filter. No point arguing with stupid people, so I left .
Then when I had my day off I dropped my car to another mechanic to do the job properly. The guy had the car from 9 in the morning until 16:30 and he calls me at 16:30 saying " I didn't have time to look at your car, come pick it up". Another bad mechanic
Now 2-3 days ago I found one of those mechanics that do house calls and fix your car at the spot. He jacked up the car drained the oil, and changed the filter. I was there the whole time watching so I am sure it was done properly . He did not not have an OBDII scanner with him. Only thing he did was look at the O2 sensor and mess with its cable a bit. I don't know if this is enough to trip the I/M Readiness INC. He told me that I should change the O2 asap as being bad it will damage other parts of the car and eventually will go in limp mode. I didn't buy his story as I think he was just trying to scare me and get the 550$ he wanted to change the sensor with a new one.
You are right I don't drive long distance. I drive like 7km to work and back and in weekends to the beach and back which is also about 7km away.
I don't have a parking space of my own I park on the street so I don't feel confident doing the oil change exposed next to the side walk. So I found somebody else to do it.
Is there a way to make sure the O2 sensor and CAT is OK. Would a professional scanner help ? maybe some other way?
Also I have tools but not car specific tools. What is the safest way for me to lift the car and do oil changes myself from now own. In my mind ramps seem to be the safest way am I right ? I can't find a proper mechanic so I might as well do the job myself.
I would go for state mechanic related courses that give you a certificate at the end but there are in another town next to mine and I can't be driving everyday for courses while working.
The only real symptom the car has is a bit bad fuel economy but that can be attributed to a million things.
Yes surprisingly the Daihatsu Sirion is a great little car with a very roomy interior.
It may have only a 1000cc engine but that is enough to spin the tires and do burnouts. It has taken me to the highway with speeds of 160km/h and up mountains with little to no hesitation.
Where I live there are a lot of bad drivers that don't care about other people on the road and the little Sirion always stops on a dime, and has saved itself and me a dozen times.
The Sirion refuses to die even if its 15 years old. It was able to drive with a bad transmission. It always started even with a bad battery. It was always there when I needed it so in the 3-4 years I have it it took good care of me so in return I do the same and I take good care of it to the point that the car has improved drastically since I got it and some people even take it for a 3-4 year old car.
I would like to add a DashCam and an Android Headunit to the car but I don't trust anybody here to do a proper job. So I have to figure out how to do them myself.
@Biomecanoid
Yes, I know. Daihatsu are great. reliable, roomy, comfortable and nice 🙂
It’s one the best small car ever made, much better then the new ones.
Also, IMO when it comes to dashcams (they’re super important, very important if someone crashes into you) it’s best to get one that just plugs in USB and hide the cable well… 👀 that’s what I do on my cars.
Sure, you can use a scanner to check on your catalytic converter performance and you don't need an expensive one
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Just get one that has graphing abilities, like a Bluedriver
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So after the O2 sensors heat up and the computer goes into CL (Closed Loop)
go to Live Data, set the display to Graph, and look at the Upstream O2 sensor (O2S11) waveform.
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It should look something like this:
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Then look at the downstream O2 sensor (O2S12) waveform.
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If the catalytic converter and the "post cat" O2 sensor are working right it should look something like this:
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If the catalytic converter or the O2S12 sensor isn't working right that downstream O2 sensor will kind of "mirror" the upstream O2 sensor and look something like this:
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Yes I should get a DashCam, I know how to get power from the fuse box and I know which camera to get but I am not sure how to remove the A pillar cover without breaking it.
Some friends of mine have done the job themselves and the A pillar cover never gets back in place 100% securely like before and it looks like someone has removed.
So I have to give it some more thought, I make RC model cars, boats and planes so I am confident around electronics.
Yes I am aware Scotty recommends BlueDriver maybe I should get one but I don't like the fact that it is not compatible with any other app apart from the original one.
What other OBDII Scanner you recommend ?
Also somebody in another forum suggested that it could be a vacuum/air leak how accurate is that and what can I do to verify it?
@BioMecanoid I do not think it's a vacuum leak, Then the engine wouldn't idle right or you'd see high fuel trims... The monitors being incomplete is not a fault, it just didn't do the check.
Well, I think he's commenting on a different issue than your I/M Readiness status
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He's probably looking at your O2S11 voltage. He'd probably like to see its average closer to 0.45 volts. Yours is at 0.395 volts. But you have a 15 year old car. Of course there's going to be a few small vacuum leaks. I wouldn't worry about trying to to push that voltage average up by 0.05 volts. I'd say "close enough". Specifically because looking at your STFT (short term fuel trim), It's at 0.0%. I didn't see your LTFT but if the STFT is at 0%, the computer is having no problem setting the LTFT to compensate for any unmetered air (vacuum leak)
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If you want to entertain a vacuum leak, Hook up a scanner, Live Data Mode, and watch your fuel trims at idle
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Let it idle for a minute for the fuel trims to stabilize. See if they're Positive. If you have a vacuum leak they'll be positive at idle. Then hold the accelerator pedal to 2500 rpms for a little bit. Do the positive fuel trim numbers go down? If so, you'd start looking for a vacuum leak. Maybe have a smoke test done on it (fastest way to find all vacuum leaks)
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As far as scanners are concerned, I'm not a "scanner snob" and I didn't mean to appear to be recommending the Bluedriver. I was just thinking of a relatively inexpensive one with a graphing option
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For a do it yourself guy, I'd say get a scanner that can display data as graphs. Also, being wireless is handy. (if you have a sensor not displaying data, with a wireless scanner you can watch Live Data while you're under the hood "jiggling" connectors and wires). If you can find one that's cheap and works with the apps you like, go for it.
Here is a video I did on the fuel trims like 2 months ago:
https://www.youtube.com/watch?v=5h2WsTMyunQ&t=48s
If you think I should do the video again let me know.
@jack63
This is the Long Fuel Trim:
?ssl=1
Well you have a steady Negative 12.5% LTFT at low rpms. "You're running rich" at low rpms. (We can't see what's happening at higher rpms)
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The thing is, don't confuse the phrase "you're running rich" with actually running rich
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The correct phrase should be, "you'd be running rich if the computer wasn't shortening the length of your fuel injector pulse(s)"
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But in your case it is adjusting them and it's at 12.5% LTFT. Well within its ability
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That's why you say it's driving and accelerating fine. The computer is making the adjustments to compensate
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You don't want to overcomplicate this stuff. All that's happening is that your engine needs a 14.7:1 air:fuel ratio
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Except for the idle air control valve, the computer has no control over how much air is entering the engine. The driver controls the air by pressing the accelerator pedal which opens the air intake plate on the throttle body
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All the computer does is to respond to the amount of air by providing the correct amount of fuel to maintain the 14.7:1 air/fuel ratio
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Your LTFT is holding steady and it isn't anywhere near its limit to adjust the fuel mix to maintain that 14.7:1 ratio entering your combustion chambers
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Your computer isn't complaining and your engine is happy
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If you want to try to push that LTFT closer to 0%, grab a can of MAF sensor cleaner and when you have a free 1/2 hour, clean your MAF sensor
With very tiny cosmetic differences this is my engine:
https://www.youtube.com/watch?v=7cfIOh6826o
https://www.youtube.com/watch?v=iBjSiZb-M4Y
I think the MAF sensor is way at the back can I clean it without removing it ?
So nothing I should do on the car apart cleaning the MAF sensor ?
This is all the readings from the OBDII after a slow 20min drive:
Bump.
Hello do you consider cleaning the O2 Sensor with Carb cleaner safe ? Like in this video ?
https://www.youtube.com/watch?v=wKOiFaNnFvU
Is the above procedure safe to do as a preventative measure ?