important information about OBD II readiness monitors
 

I think there's a lot of confusion floating around about what inspection "readiness" really means.

Here's how it works. OBD II was designed to make tailpipe testing unnecessary. Therefore the PCM tests the emissions control systems on its own. The ECU can't always take a "snapshot" of sensor data to know whether a system is working right. It takes time and certain types of driving conditions to know for sure.

The most common/important tests that need to be flagged "Ready" are:

-- Catalytic Converter test: the PCM monitors rear O2 sensor voltage over time to see if your cat is working right

-- Evaporative system: the test that makes you throw a code when the gas cap is loose. EVAP systems are actually crazy complicated.

-- Oxygen sensor: the PCM checks for a particular signal curve over time. The exact test depends on the sensor's position (Front or rear) and whether it is a wide or narrowband sensor. There's also tests for the the O2 sensor heater.

After you disconnect the battery or clear codes, most of the readiness monitors go to "Not ready."

https://www.rx8club.com/attachment.p...1&d=1261276930


It is a myth that you need to drive x miles for the car to be "ready" for inspection. There's no set number of miles. I've passed inspections after less than 50 miles of driving sometimes. It just depends.

The Do-It-Yourself OBD II Inspection

The best way to determine whether your car is ready for inspection is to hook up to a higher end OBD II scanner if you have one. I have one of the big orange Actron scanners (Actron CP9180) that you usually see being used by auto parts store employees. It was maybe $120 new off ebay when I bought it a while ago.

Now I'm going to demonstrate me checking to see if my car will pass inspection. This is my daily driver, a 1997 Infiniti Q45. My 1988 Rx-7 Turbo doesn't even have a check engine light!

https://www.rx8club.com/attachment.p...1&d=1261276930

The first shot here is of the main menu in the Actron CP9180. I have two choices. I can select "State OBD Check" to get a summary of my readiness monitors and DTC's. I can also select "I/M Monitors" to get a breakdown of all the readiness checks in the PCM. So first I select "State OBD Check."

https://www.rx8club.com/attachment.p...1&d=1261276930

From this screen I can see that the check engine light (Malfunction Indicator Light) is not active. I do have one DTC however, but it is a "pending" code that has not yet tripped the MIL. This number could be "3" if I had two active codes and one pending code.

Then the scantool separates my readiness monitors into 3 categores: OK, Incomplete, or Not Applicable. Any 2001+ car must have all but 1 supported monitor set as "OK." Only 1 readiness monitor can be set flagged as "incomplete." This car will pass an inspection because the MIL has not been set and all monitors are ready. Now let's take a more detailed look at my list of readiness monitors in the "I/M Monitors" screen.

https://www.rx8club.com/attachment.p...1&d=1261276930

Those top three are my continuous monitors. Those three are always active. Any monitor that is not supported is listed as N/A. This particular car has an EGR readiness monitor but it does not have an EVAP monitor.

https://www.rx8club.com/attachment.p...1&d=1261276930

Any monitor that requires some sort of drive cycle is called a non-continuous monitor. Those are the ones you are waiting on when you visit the inspection station. In my experience the Catalyst monitor and the EVAP monitors take the longest to be set.


I hope that clears up some confusion about OBD II inspections and "readiness" tests. Engines don't just arbitrarily become "Ready" after x number of miles or x number of drive cycles. PCM's go through a series of tests to make sure the components are working, and different criteria must be met for every engine. A lot of inspectors really don't understand this system fully. They just do whatever their inspection tool tells them.

A sample drive cycle that may help set readiness monitors:

https://www.rx8club.com/attachment.p...1&d=1261277575

Thanks for posting this up. It's very informative.

If there's someone with a service manual: I wonder if it contains the RX8's specific drive cycle requirements.

Good idea. Here's the drive cycle in the service manual.

https://www.rx8club.com/attachment.p...1&d=1261341363

jackpot!

That's great stuff.

It's just standard service manual information :dunno:

buy one and read it, you'll like it ....

.

I ran the drive cycle today specified from the excerpt from the manual. I should be able to bring it in either Saturday or Monday next week and will report back.

Service manuals can be tricky to navigate if you don't have much experience with them.

I went back to the emissions testing station today and am still not "ready." they stated the cat sensor and O2 sensor are not ready yet.

I called my Mazda dealer and they said it should take 4-5 drive cycles (cold start to full warm) but that there was no special drive cycle for these sensors just put some miles on the car. Any thoughts or suggestions? At this point I have put 5 drive cycles on the car and ~150 miles on it since I re-installed the AP and cleared the memory.

I think I should be good to go at this point but clearly am not so I'm nervous about not being able to get the sensors to set and not being able to pass emissions before the end of the month. Any suggestions on this would be appreciated.

Just took it back after putting on two more cold start drive cycles and 200 miles on the car and still "not ready" :(

any other specific drive cycle info? Jeff mentioned it may take a certain amount of full warmup cycles due to the cold.

Well I unplugged the AP and as soon as I turned the car off and on again I had a CEL. I had the DTC read and pulled a P0037. Low voltage for H02 sensor #2. So my cat. sensor doesn't seem to be working. That would explain why the sensor was tripping. It's at the dealer now and they're checking it out...

Edit: The dealer has confirmed it's the cat. sensor. They've replaced it and recommended 2-3 cold start to warm up drive cycles. Hopefully I can get this done by Saturday and bring it back for an emissions check.

I passed the OBDII emissions check today. The bad sensor was the problem. Because I had a bad sensor when I reset the computer it could not set the readiness monitor (rightly so). It easily set once the cat. O2 sensor was replaced. The MM AP tune masks this CEL so I didn't know I had a bad sensor until I uninstalled the AP.

This worked like a charm for my 09 R3. It was stuck in Not Ready mode for about 30 miles after disconnecting the battery and this fixed it by mile 51.

Thanks.

Thank you everyone, and special thanks to the OP. BEERS!
This thread has been a huge help to me.

I know this is a bit of a bump but I think this is a very helpful thread
Background:

- Location Ontario Canada
- Boosted top mount design running Cobb tune NO masked cels
- Last time car was tested 2012 by sniffer test and passed (car was stored for a few years)
- ODBII Drive Clean test implement 2014 (I think)
- Catalytic installed including Rear O2
- Secondary Air pump connected both electrically and to the manifold. However I did not use the solenoid/diaphragm/vac hose connections. Connecting the Secondary is the only way I could get the "READY" for AIR

- In Ontario we are allowed 1 "NOT READY".

- Important point for Ontario peeps, you are only allowed 2 yes 2 temporary 10 day plate stickers after that you are toast. And yes the guy at the garage told many stories of average peeps with normal cars that could not get a "READY" and had to drive on a expired plate sticker. From what I could tell from Tech Dewd this seems to be a particular problem in the winter trying to get the emissions to "READY" (so make a note of that if you need to get a emission test in February). Tech dude also said it's mostly the EVAP that doesn't "READY".

- I followed the above drive instructions and everything worked great, except EVAP .. that's black magic.

In a nut shell. From a reset ECU this morning I performed the above procedure and was passing drive clean with one "NOT READY" EVAP in the same day.
Done and Done

wonder if you could pass with midpipe if you time the test just at the right time?

I've heard of one trick where you can install a spacer to pull the rear O2 sensor out of the exhaust stream to fool it if you're running cat-less.

https://cimg0.ibsrv.net/gimg/www.rx8...f1f46ece09.png

Yes, I'm serious, Fry.

Just so this bad information isn't left hanging out there: This does not work for any car with an ECU designed in the early 2000's and later. This includes the RX-8.

It does work on cars with older OBD-II ECUs from the 1990's that don't have countermeasures to detect it. Later ECUs have countermeasures to detect these tricks and trip a CEL.

Thanks, I have since learned why I was wrong.

sometimes people will think the cat is bad and then realize it was the sensor after replacing with a new cat and light still their. If u use the defouler spacer trick with a known good 02 sensor you wont get a circuit low code

No, the defouler trick does not work on the RX-8. Period.

That may cure the P0420 code but it will cause a P0139. The PCM is smart and deliberately runs lean/rich cycles with a specific frequency. If the O2 sensor output doesn't respond correctly (if you've tried to fool it with an anti-fouler), it will throw a P0139 code.

your wrong Period. Unless you can show me it didn't work your all just talking off of reading someone else's notes a bunch of bull shit with no trial. Most of y'all rx8 owners can't find your belly buttons and don't do any of your own work and only listen to others opinions and bs diagnosis instead of testing and assured by them selves. it's fine I'll just keep buying up rx8 from rx8 owners who don't know shit and get pushed into doing costly stupid repairs saying it's the right and only way and end up selling. theirs o2 emulator modules in the market also that this car doesn't need. a couple defouler stacked works along with a set of brains

no codes no cat over here in Texas

That's one way to make new friends. :rolleyes:

Allow me to point to the anti-foulers I tried, that utterly failed:

https://cimg5.ibsrv.net/gimg/www.rx8...bfb5340a2b.jpg

Many have tried, all have failed. You must be very lucky, a genius, or a liar. I'm not sure which. :dunno:

You're just lucky, they will come eventually.

2500 miles track and road not yet

I have more than 10k hours in automotive technology though

oscilloscope will show you what your ecm can see from the sensor if you can access one of these u can even build your own board to manipulate stoich readings.

Cool story, you and every other mechanic that I know more than.

its funny I have shops in San Antonio, Austin even Dallas that call me over from Rosenberg Texas for electrical diagnosis. I can have it diagnosed and repair under cost of the dealer with the same tools and do on the spot programming. Plenty of great mechanics not as many electrical engineers who will work on automotives as well as diagnose them.

Yeah every mechanic thinks they are a good mechanic. And most shops sucks, I rarely meet a mechanic who knows what they are talking about, especially dealer "techs" who diagnose by parts replacement.

Oh, and that is one of my favorite rap tracks.

Oh, and spark plug foulers don't work.

say what you will, quite a few people dont like 9ks attitude but he has been here from the start. he has a ton of info and experience with 8s. he can be very helpful as long as you dont want to be spoon fed and ask newb questions, we have heard them all.

that being said i want you guys to tell me step by step how to do an rew swap making 500+whp for ~3k

Attitude? Me? No way. If I do it's because of noobs who drop in thinking they know more than the 15-16 years worth of info here.

stfu fool, you dont know shit cause you didnt answer my simple ass question. my mechanic said it would cost about 3k

Thank you for that. The last part was legitimately confusing.

aww your feelings are hurt so u went from o2 sensors and defoulers to 16 years of knowledge being disregarded.

LOL an electrician will know how to full your o2 sensors; any one with the right tools and skill set could do it. Most mechanic shops dont do upholstery, stereo installs, body work or electrical so why would you expect them too. If a shop is pretending to be your one stop shop likely your going to get half ass work all the way around or they contract out certain jobs to other shops and engineers. Your good at running your mouth about bull shit on a forum 9k. I will only expect so much from you as you have been doing so for 15 16 years.

I don't have feelings, electricians don't work on cars, and no one wants to "full" their O2 sensors.

And I'll put my knowledge and my RX-8 against yours (well if you can call it that) any day fruity.

That's enough...thread closed

FWIW....the anti-fouler type O2 foolers will not work on this car or any newer OBD compliant vehicle

Sometimes they work for a while...just like nothing seems to work for a while sometimes on some cars. Sooner or later though they CEL will appear