Smog Geeks: Help needed: "OBDII Monitors Not Ready"

Ever since I had the Fabspeed exhaust installed (full kit: headers, X-pipe, mufflers, cats), I have been plagued with CELs (P0420 and P0430 codes). Earlier this year I had O2 sensor extenders put on, in the hopes that would solve it. Nope. So, periodically I clear the codes. They pop up again, sometimes after a few weeks, sometimes after a couple months. My smog inspection is due, so I cleared the codes a few weeks ago. I've driven the car maybe 400 to 500 miles since then, and no CEL/codes. Today I took it in for a smog inspection and failed because it reads "OBDII Monitors Not Ready." The guy said I need to drive the car some more to reset the OBDII monitors. I would think that after a few hundred miles they would have reset by now. Any chance the 02 extenders are preventing this? Suggestions on what to do? Thanks!

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You just need to keep driving. Get yourself a BT odb2 reader and check the monitors yourself. I had one car took over a month before the monitors were ready. Drove over 1000 miles.

Thanks, Stan. I have a Bluetooth OBDII reader. I can scan for codes and clear them, but not sure how to see if the monitor that it is looking for is "ready." I use the Torque Plus app.

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Same here. The shop told me to drive it for 80 - 100 miles.... Over 3,000 miles! It will eventually come around.

Yowza! I have only until January 2, so no way I'm putting on that sort of miles between now and then. Also, likely the CEL will pop up again within 3,000 miles.

Sorry, I meant use the reader to monitor ready status. I use torque too, and use it to make sure my car is ready before I head to the smog shop. As for how long it takes the car to ready itself, that is a mystery to me. My mechanic said a few days, but yeah - took a lot longer than that on my car. I think 2 things are the culprit here. The 02 sensor, or the cats itself.

Cuda, if you use Torque Pro the readiness flags are shown in the second screen to the right of the home screen. Your catalyst flag is not set most likely is because your cats are marginal (from the dme's point of view) so some of the cat tests failed (there are multiple sub-tests that need to pass before the dme sets the readiness flag). The dme is retrying those sub-tests and if more those failed, the CEL will be tripped. Also the sub tests may pass or fail randomly due to the "marginal" nature of the cats. You can try to drive more miles and if you're lucky that all the stars line up, the flag will set and you should rush to the smog check before some of those sub-tests fail again.

To expedite the cat sub-tests, just keep the engine below 3k as much as possible when driving both highways and local roads.

had this problem a few months ago...ended up needing new cats P.S. Luckily, I had just passed smog when it acted up

The cats are pretty new, less than 20K miles on them. They are Fabspeed cats though (stamped "HJS Tuning)... 200 cell high flow, so not OEM. I replaced all four O2 sensors when the cats were installed (August 2014). Two years ago it passed with these same cats (smog cert is every 2 years), and the only thing different is that I didn't have the 02 extenders on last time. Think that makes a difference?

Mike, a PIWIS has a short test function to make everything ready. Last time I did it from a complete reset it took just a few minutes and maybe half a mile of driving once the engine is warmed up, barring your car is mechanically OK. PM me if you want to stop by to give it a go; I'm not far from you.

PM sent.

Mike, our cars are identical. I passed mine smog test in AZ 1 hour after resetting everything, roughly 25 miles after it. What I did was FOLLOW the drive cycle procedure to the T. This is what I did. I cruised at low speeds on 19th ave in Phoenix to get the timing. And timed myself with stopwatch. DO NOT EXCEED 60 MPH AT ALL COSTS!!! Start engine, let idle for approx. 2 min, 10 secs. Accelerate to 20-30 MPH, Maintain steady speed for approx 3 min, 15 secs. Accelerate to 40-60 MPH, Maintain steady speed for approx 15 mins. Decelerate and come to a stop. Then: Idle in Neutral for 5 mins. (manual trans.) Idle in Drive for 5 mins. (Tiptronic trans.) During the drive cycle, do not exceed 3,000 rpm or 60 mph.

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Is it possible that the status was ready at some point, but then became unready just before I took it in? The car hadn't been driven in a few days, so just before I took it in, I took it for a short freeway drive to get the cats hot, so purposely kept the revs maxed for about 10 to 15 minutes just before the smog test. Kalash... thanks... I posted a similar thread on 914World (lots of great technical guys there) and someone posted a 993 reset protocol. I will try the one you posted.

Wrong ^^. Reset all monitors and follow my procedure. Don't shut off the car before smog test. That is what I did, and I had a constant SAI pump error triggering CEL. Car passed the test. Edit, 993 and 96 should be identical. It's been almost two years. I recall googling it then, the 993 protocol is what I used (at least what I recall...I've been out drinking tonight). I know that it worked.

Will do, thx, will also do Garretts's PIWIS protocol. Did I ever mention that I hate the government weenies? Yes, I have, many times, but I will use this place to reiterate it.

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Had to clear error codes a number of times in both my Boxster (an intermittent P0430 due to a loose converter brick) and my Turbo (misfires at cold engine start) and the readiness monitors are always set to complete in 30 miles which is just my home to work commute. I don't keep RPMs below 3K I just avoid hammering on the engine. I mean once warm the engine sees revs above 3K sometimes quiet a bit above 3K but I don't strive to keep the RPMs maxed out. In your car's case keeping the revs maxed out was the problem. Under hard acceleration/high load conditions the DME suspends converter monitoring and this delays or even resets the converter readiness tests.

You need to drive the reset cycle. A bunch of threads here and other forums on resetting the readiness monitors. Its a PITA What Kalash posted sounds right and dont exceed RPM or speed or you need to start over

Thx, will do!

I almost always reset readiness monitors by starting with a cold car. Then I start car and turn on everything electrical. Then let it idle until nice and warm. Then just go for a drive. This usually works.

This is the correct procedures. Short cuts may not work for some monitors. "Mike, our cars are identical. I passed mine smog test in AZ 1 hour after resetting everything, roughly 25 miles after it. What I did was FOLLOW the drive cycle procedure to the T. This is what I did. I cruised at low speeds on 19th ave in Phoenix to get the timing. And timed myself with stopwatch. DO NOT EXCEED 60 MPH AT ALL COSTS!!! Start engine, let idle for approx. 2 min, 10 secs. Accelerate to 20-30 MPH, Maintain steady speed for approx 3 min, 15 secs. Accelerate to 40-60 MPH, Maintain steady speed for approx 15 mins. Decelerate and come to a stop. Then: Idle in Neutral for 5 mins. (manual trans.) Idle in Drive for 5 mins. (Tiptronic trans.) During the drive cycle, do not exceed 3,000 rpm or 60 mph.

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Ahsai, what screen do you mean? This is what the app looks like.

Under "real time info", then try swiping the screen left and right. There should be some default screens.

Should look like this

Thanks! I never would have found that menu.

OK, so I followed Kalash's drive cycle procedure. Holey swiss cheese, Batman!! it ain't as easy to do as it sounds. Before the procedure I had "incomplete" next to "Catalyst." Now it says "complete," so am I good to go? Smog guy is closed today. I sure hope it says "complete" when I scan it tomorrow morning.

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Yes, you are good to go. Whatever you do, dont do an erase all codes!

Yep, and gonna drive like a little old lady to the shop. Or like JG, same diff.

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At least when I got tagged by CHP I was doing 107

Hey, missed ya at the QC AX track on Saturday. Low turnout and great weather, so we got tons of laps in.

If any of you are still up posting tonight.... should I take the car for a drive before the smog check to heat up the cats (but not whomping on it like I did last time)? Coulda sworn that last time I had my smog check someone told me to get the cats good and hot (which is the reason I drove it so hard before the test a couple days ago). The smog place is only a mile from my house, so they won't be at temp if I just drive straight over there.

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That was the rule of thumb for a car that can barely pass the sniffer. I wouldn't even bother. Last time I smogged my car, they didn't even put it on the dyno or sniffer. Just plugged in my ODBII port and I was out in a few mins. That was a '05 car though.

Yeah, but I have to do one of those rip-off "STAR" inspections this time, so the will do dyno, etc.

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Yea, I was thinking of doing it, but went out to the desert with my wife as it was the last weekend we can use our condo until probably April or May as we have it rented out. Also wanted to save my tires for next year

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IIRC, the STAR testing is no different from regular stations, just OBDII

silly question but wont it fail the visual inspection?

I hope you don't get hosed by the STAR inspection - the visual inspections I've had the past few years have been VERY comprehensive...

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The requirements are the same, but the STAR stations are held to a higher standard than non-STAR stations. The same STAR shop did both my 996 and my Corvette; since the 996 is (according to the paperwork) AWD, they did not dyno it. They DID dyno my Corvette. My old guy plugged in the OBD-II, tested the gas cap, and sent me on my way; the STAR stations I've been to have guys with flashlights and inspection mirrors; they spent WAY too much time poking around. Here's what BAR says about STAR stations: "STAR stations are Smog Check stations that meet higher performance standards established by the Bureau of Automotive Repair." And this is why you got sent to a STAR station: "All 1999 model-year and older vehicles (the model years most likely to have high emissions) will be directed to STAR inspection stations." Basically, BAR got wise to the fact that people have "friends" who were hooking them up; they started randomly performing roadside emissions testing. Mysteriously, 19% of cars that had recently passed a shop smog test failed roadside testing.

I'm in the same boat.....need to find a place here in SD where I can actually do the drive cycle......ugh. Glad to hear it worked for you. I was also told that re-flashing the ECU via Porsche dealer will achieve the desired result. Anyone know whether that's true or false?

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A one mile drive while it will have the DME in closed loop mode the converters may not yet be at their optimum temperature. I wouldn't risk a failure due to "cool" cats if I were you. Just drive the car around to ensure the engine and converters are thoroughly up to temperature. There is no real science to this: I spend at least 30 minutes just driving around with a mix of city and freeway driving before taking either of my cars in. I don't really hammer on the car nor do I drive it like a little old lady. If you suspect the converters may not be working at their best my experience is a bit of an "Italian" tuneup can help. Couple of years ago my Boxster failed its smog test. The snifter found IIRC too high of CO2. I immediately went to the dealer and spoke to both senior techs, separately. Both gave me pretty much the same response and advice. Both senior techs were surprised the car failed and both advised me to take the car out and really drive it, if you know what I mean, and I think you do. So I did but encountered a CHP cruiser on the way back home so had to cool my jets the last 15 miles or so. Still I maintained freeway speed though. A few hours after the 1st test I had the car right back at the same station for a 2nd test and this time the car passed with no problems.

Thanks, Mac. Headed out in about an hour or so, will report back.

Good news... PASSED!!!! Thanks for all the help, guys!!! Was sweating it big time, since he failed the car in front of me for not having California certified cats.

Man, you scored. Congrats! I stopped using aftermarket emissions-related stuff after having to take off my long-tube headers to get the 'Vette smogged a few years back. When I put 'em on, I figured worst case, I'd have to swap 'em out every 2 years...which sounded a lot less of a hassle than it turned out to be.

Have you guys tried spark plug non-fouler's on the cat sensors? Worked for me on other cars with headers.

Hey guys, So I'm having a similar issue with my SAI and O2 being in not ready status. A little background about my car. 2006 Boxster S 3.2L FVD Exhaust system GMS Headers with 200 cell cats - has all 4 O2 sensors attached. 996 throttle body and distribution hose ECU Tuning Group tune. I had the car up in BC Canada since 2009 (although it is a US car) and had no problems passing the sniffer and obdII tests - both before and after all the mods except for the ECU tune. This is the first time I am taking the test with the tune on the car. I went to get my emissions testing done last week in Texas and failed due to the 2 systems being in not-ready status. I figured it might have to do with the cat delete configured in the tune. I sent my ECU back to ETG in California and had them re-flash my ECU in order to re-enable the O2 sensors. I cleared all codes and figured I would start fresh. I drove the car about 50 miles and attempted to follow the drive cycle you guys mentioned but it was really tough with the roads out here. Anyway, everything is in ready status now except for the Evap System (Which I know will turn on after some more driving), the SAI, and the O2 sensor. I can manually start the SAI using the Durametric system so I'm fairly positive the system is not bad; however, I'm not sure that I"m hearing the SAI start up when I cold start the engine. I've attached a picture of the ready-status' from my DashCommand IOS app as well as another screen showing N/A for catalysts and O2 sensor - which i don't get. I would expect to see live results there. I have also included a short video of a test I ran with the durametric system. If anyone can help interpret the video results and/or suggest I run any other tests, I would appreciate that. Thanks!

When doing the "drive cycle" your fuel level needs to be between one half and three quarters.It affects the monitor self test for the evaporative ,oxygen sensors and cat tests.I have been a smog test and repair tech for over 30 years [now retired] ,the drive cycle monitor test can be tough to complete.Follow the procedure in shop manual .

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Your oxygen sensors do not appear to be returning any data - voltage nor temp - which makes me wonder if they actually are enabled. If they were enabled but failing, I'd expect to see some values, but your OBD software is indicating "N/A" for both data points...

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@garrett376 can you point out where those test functions are in piwis? do you have to drive the car with piwis connected to go through those test functions?

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Should be under DME: Maintenance and Repairs: Special Function: Short Test

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@garrett376 thanks I found them in piwis and tried to do them, however, had mixed results on the lists of tests and I'm not sure if it's ready for test at the inspection station... guess I'll just give it a try (you can find details of my short test results here: https://rennlist.com/forums/997-foru...l#post18530738 )

I'd be happy to come by at your convenience.I'm in Pt. Loma Pardon my ignorance, but what is PIWIS?

Porsche Integrated Workshop Infomation System (PIWIS) / KTS-650. The PIWIS is the latest Porsche diagnostic tool, and is similar to the Porsche System Tester 2 but also supports CAN-BUS vehicles. PIWIS also integrates repair manual information into the diagnostic tester. Porsche dealers use this proprietary software to set readiness monitors in the ECU so the techs don't have to do the driving required to set the readiness monitors after a car has been in the shop.

IDK how you guys figured this sourcery out....but I'm super grateful you did! I live in Denver and took my 2003 996 in yesterday and it didn't pass as the car had been sitting for a bit. I found this thread and followed the directions as closely as I could (I'm adding two more steps for people who live in Colorado) : During the drive cycle, do not exceed 3,000 rpm or 60 mph. Have gas filled between 3/4 - 1/2 Start the engine, and let idle for approx. 2 min, 10 secs. Accelerate to 20-30 MPH, Maintain steady speed for approx 3 min, 15 secs. Accelerate to 40-60 MPH, Maintain steady speed for approx 15 mins. Decelerate and come to a stop. Then: Idle in Neutral for 5 mins. (manual trans.) Idle in Drive for 5 mins. (Tiptronic trans.) DO NOT SHUT CAR OFF The Emissions Rep will make you sign a non-liability clause for not shutting the car off. (Try not to smile too much as this crazy thread you found online actually worked) That did the magic for me. I should add I didn't have any of the code readers (or apps) that other members are using. I just followed this as close as other drivers on the road would let me!

June 2024, can confirm this procedure works on a 996.2 Did not pass due to cat not showing ready on the OBDII. Had driven 2.500 miles since last battery swap. Regular drives don't seem to do the trick, as anything above 3K rpm cancels the cycle, so basically as soon as you leave your driveway. The drive cycle procedure seems more designed for a controlled dyno setting than open roads. I did the cycle in the evening with minimal traffic. First try, and it worked. In the last step I only idled for 3 min. Drove normally after, did the smog test two days later, so stopping the engine did not seem to have any effect on mine.