In Calif. 2000 Z3 OBD II "Not Ready" for months

[BimmerBreaker]

Took it to the dealership, because DMV Referee said that BMW dealership repairs are the only one they recognize (I suppose if you spend over a certain amount and still can't pass, they might waive the test) dealership recommended new cat, but can't say that will fix it.

Do they look at the receipts of repair work or something? Whats stopping you from going to a third party exhaust shop, getting a new aftermarket cat welded on, and then driving back and saying "oh yeah I don't know, the CEL just went off on it's own a couple days after my last emissions test"? Do they do a visual inspection? If so would it even be a problem as long as the catalytic that was installed met all emissions guidelines?

[Henryz3]

Attachment 576172

Follow this twice (back to back) and you should be good to go.

My CAT was "Not Ready" for a month (in California) until I follow this twice then eureka! it was fixed.

Had about 10 people try to run me off the road when I maintained 20-30mph on the freeway for 3min 15sec. :p

This is the exact Drive Cycle I tried, even had the shop hold onto the car for 6 weeks so they could try it. Put on nearly 1k miles trying to get this drive cycle to work. Everything passes except CAT NOT READY. CA DMW wont pass the car.

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Just needs to pass. If driver is considered low-income, there is a waiver of something like $300-$500, otherwise there is no limit, but you have to have the dealer do enough to satisfy the DMV referree that you have done enough, It's a judgement call on their part.

[rf900rkw]

Considered a road trip to the east coast?

[djb2]

I see that I never updated my situation.

Replacing both upstream sensors and one of the two downstream sensors set the monitor 'ready', despite no indication that the old sensors were bad. I immediately went in and passed the smog test.
The cheap eBay sensors died in a little over a year, just as others have experienced, but they were worth it for the diagnosis.

I rarely suggest shotgunning new parts at a problem, but this is an exception. You can get all four sensors for under $50 and put them on in an half hour or so.

[me77]

I also have the issue that the readiness monitor for the O2 sensor never sets to READY. It always stays at NOT READY, but all the other monitors go to ready within a week of driving (around 200 miles). I followed the picture from post #15 but it didn't work. In the state that I live in, it can pass with 2 monitors not ready so I don't worry too much about it. I never had any trouble codes stored and no CEL, MPG seems ok to me.

...I rarely suggest shotgunning new parts at a problem, but this is an exception. You can get all four sensors for under $50 and put them on in an half hour or so.

Where can you get them that cheap?

[328 Power 04]

This is the exact Drive Cycle I tried, even had the shop hold onto the car for 6 weeks so they could try it. Put on nearly 1k miles trying to get this drive cycle to work. Everything passes except CAT NOT READY. CA DMW wont pass the car.

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Just needs to pass. If driver is considered low-income, there is a waiver of something like $300-$500, otherwise there is no limit, but you have to have the dealer do enough to satisfy the DMV referree that you have done enough, It's a judgement call on their part.

Send me DME, or have an OBD cable for a custom flash, and lets pass that car...

[djb2]

I also have the issue that the readiness monitor for the O2 sensor never sets to READY. It always stays at NOT READY, but all the other monitors go to ready within a week of driving (around 200 miles). I followed the picture from post #15 but it didn't work. In the state that I live in, it can pass with 2 monitors not ready so I don't worry too much about it. I never had any trouble codes stored and no CEL, MPG seems ok to me.

Where can you get them that cheap?

FleaBay. Don't expect them to last, but you might get lucky.

If you really want to diagnose, put all four in long enough to pass, then put your old upstream sensors back in. Reset and see if the monitor is set to ready. Figure out which sensors are slow, replace them with high quality ones, and store the cheap new ones for the next time you need to pass emissions.

I find most of the diagnostic information directly useful, but emission monitors are pretty opaque. The ECU will simply report that there is no error, not letting you know what it thinks isn't quite right.

[jclausen]

To set cat monitor this has worked for me on really stubborn cars I do a 40 minute drive, no brakes applied, 40-60 mph, rpms below 3,000. No quick acceleration and while driving include short coasting periods while staying above 40 mph. If there is any pending faults but the check engine like is not on that could stop the monitor setting process. This test drive is slow, drive in the slow lane with 4'way flashers on. I would recommend driving it when traffic is light. I have driven customers cars at around lunch time, I have done this test may times and have always gotten the cat monitor to set

[Blacksheep]

I had this happen after my restore. Months later I needed the smog for registration. I failed the OBD . WTF?

Even after driving 30 miles I failed.
I drove 60 freeway miles and went straight to the smog test.

PASS!

Go figure.

[jclausen]

Here is Drive cycle i use for Cat monitor problem cars. 40-60 mph, no quick acceleration, under 3,000 rpm, no braking, intermittent coasting, drive on freeway slow lane, for at least 20 mins, I had to drive a e46 m3 for 40 mins. It Is about flow of exhaust and how it process's it and at the slower speeds enough time for the heat to get into the cat I believe. It may take a couple of these drives, but it has worked for me

[thecaines]

Again. If you had a component failure, or a plugged air passage (that is a V8 specific problem), your test would not pass and you would see "Fail". The "Not ready" means the test hasn't run to completion. This is not the same as ran and did not pass. It means conditions were not right, or changed, for the test to be run.

This is probably an old post, but people check them all the time so here's some input. I had a 2000 Z3 with only the Cat monitor INC, but no code indicating any failure. When I looked at the live data with my OBD2 tool, the Cyl 1-3 downstream O2 sensor read about 0.75 volts while the Cyl 4-6 sensor read 0.1 volts. This, along with noise like a leak forced me to remove the Cyl 4-6 cat (removed both by necessity). Once it was out, I discovered the rear cat was in 2 pieces!! But it gave the downstream O2 sensor a nice steady BAD signal so the car did not see it as a failure. It did, however, refuse to complete the CAT monitoring cycle because the two downstream O2 sensor readings were so different. Definitely a lesson from the school of hard knocks!