[csu87]

depending on the county in CO, youll pass. When I went in for my emissions, they didnt pull any codes or check for any readiness. You drive by a sniffer as you drive into the facility, coasted through it in neutral, and then they just look for check engine lights.

[V8bait]

Originally Posted by feuer

With catless DP's it will fail 3 to 4 system readiness monitors: 1-cat 2-pre cat o2 sensor 3-post cat o2 sensor and possibly 4-evap
So even if they let you pass with 1 fail it will not happen with catless DP's.
1 fault like failed purge valve causing failed evap would be pass.

Wrong. Literally everything you said is wrong. Even the last sentence. You cannot fail a single monitor. There's a difference between FAIL and NOT READY. And the other stuff is pure fiction created by your lack of understanding about how emissions equipment, monitors, and testing work.

You should read more and post less.

[Gohan335i7]

Why these emissions tests? Just leave these people be , damn... Catless sounds amazing & from what I have read allows your turbos to breathe a lot better than catted so Let the Turbos breathe!! Haha!! Stupid law IMHO...

[feuer]

Originally Posted by V8bait

Wrong. Literally everything you said is wrong. Even the last sentence. You cannot fail a single monitor. There's a difference between FAIL and NOT READY. And the other stuff is pure fiction created by your lack of understanding about how emissions equipment, monitors, and testing work.

You should read more and post less.

I wrote above post only because I gather people expect to PASS emission test with CATLESS DP because one NOT READY is allowed. Now on your remark for FAIL or NOT READY, different yes, but vehicle will not PASS the emission test successfully so overall result would be FAIL if system reads NOT READY and vehicle can not be registered. I take cars to emission testing frequently and have had cars pass with single monitor NOT READY like EVAP or EGR of even MISFIRE but CATLESS DP triggers multiple system monitor to show NOT READY like for the CAT itself and the O2 sensors which is 3 system monitor NOT READY not 1. So please do not be harsh for word usage. If needed I can attach photos from paper work if still not clear of what I want to explain. Is Monday and I had two cars for testing already...

[V8bait]

Originally Posted by feuer

I wrote above post only because I gather people expect to PASS emission test with CATLESS DP because one NOT READY is allowed. Now on your remark for FAIL or NOT READY, different yes, but vehicle will not PASS the emission test successfully so overall result would be FAIL if system reads NOT READY and vehicle can not be registered. I take cars to emission testing frequently and have had cars pass with single monitor NOT READY like EVAP or EGR of even MISFIRE but CATLESS DP triggers multiple system monitor to show NOT READY like for the CAT itself and the O2 sensors which is 3 system monitor NOT READY not 1. So please do not be harsh for word usage. If needed I can attach photos from paper work if still not clear of what I want to explain. Is Monday and I had two cars for testing already...

Still wrong. Please, stop. O2 readiness, evap, trim control, etc etc can all be met with catalyst not ready. EGR on a n54 does not even exist as a monitor and reads as n/a. I'm glad you take cars for testing. I tested them.

[feuer]

Originally Posted by V8bait

Still wrong. Please, stop. O2 readiness, evap, trim control, etc etc can all be met with catalyst not ready. EGR on a n54 does not even exist as a monitor and reads as n/a.

I'm not an emission expert. It is just a errand I do and I'm not talking about N54 specifically, neither saying that all above CAN NOT be meet with CAT not ready. I just wrote from what I have seen when vehicles with no CAT or deffective CAT go to emission testing. Usually shows the O2 sensors as well. For example customer comes with CEL and is leaking purge valve shop will repace it then erase the CEL. Car passes. When they do the same with the CAT car does not pass. Meybe you know why this happens and if so explain.

[V8bait]

Originally Posted by feuer

I'm not an emission expert. It is just a errand I do and I'm not talking about N54 specifically, neither saying that all above CAN NOT be meet with CAT not ready. I just wrote from what I have seen when vehicles with no CAT or deffective CAT go to emission testing. Usually shows the O2 sensors as well. For example customer comes with CEL and is leaking purge valve shop will repace it then erase the CEL. Car passes. When they do the same with the CAT car does not pass. Meybe you know why this happens and if so explain.

If primary O2 fails, car runs pig rich, cat melts, secondary O2 fouls, all fail readiness, test fails.

If purge valve or gas cap leaks, EVAP fails, test fails.

If cat fails, test fails.

If any single monitor fails, test fails.

If one monitor is not ready, test can pass if it's just one monitor, any monitor, in most states.

Secondary O2 monitors failing will result in cat readiness reading not ready or failed (despite condition), and a failed test.

Secondary O2 monitors cat efficiency. O2 readiness is not related to cat readiness. However, on a stock tune, ready O2's will eventually lead to the not ready cat (deleted or just bad) reading as failed thus failing the test.

In Colorado, unless they've changed things, failed monitors only send you to the sniffer, which you can still oftentimes pass with every monitor failed. (Unlikely and extreme example, but if the car is running that good it almost deserve to pass at that point). Colorado emissions only exist in Denver, and are more wholistic in that they just don't want poor running cars on the road. It's carryover from days when carburetor equipped cars driven by Californians were moving in masses to the beautiful and high altitude Colorado without adjusting the jets, and turning the clean air into a liberal cesspool of smog and smug resembling LA.

f'kin e90post. When I used to test cars, I would have failed you all because I was that guy who actually looked for cats. Yep. All of you. :-)

[csu87]

Originally Posted by feuer

I'm not an emission expert. It is just a errand I do and I'm not talking about N54 specifically, neither saying that all above CAN NOT be meet with CAT not ready. I just wrote from what I have seen when vehicles with no CAT or deffective CAT go to emission testing. Usually shows the O2 sensors as well. For example customer comes with CEL and is leaking purge valve shop will repace it then erase the CEL. Car passes. When they do the same with the CAT car does not pass. Meybe you know why this happens and if so explain.

This is a BMW forum and the thread is about passing in a BMW. Doesnt matter what other cars you've taken to get tested at this point unless it's an N54.

Originally Posted by V8bait

If primary O2 fails, car runs pig rich, cat melts, secondary O2 fouls, all fail readiness, test fails.

If purge valve or gas cap leaks, EVAP fails, test fails.

If cat fails, test fails.

If any single monitor fails, test fails.

If one monitor is not ready, test can pass if it's just one monitor, any monitor, in most states.

Secondary O2 monitors failing will result in cat readiness reading not ready or failed (despite condition), and a failed test.

Secondary O2 monitors cat efficiency. O2 readiness is not related to cat readiness. However, on a stock tune, ready O2's will eventually lead to the not ready cat (deleted or just bad) reading as failed thus failing the test.

In Colorado, unless they've changed things, failed monitors only send you to the sniffer, which you can still oftentimes pass with every monitor failed. (Unlikely and extreme example, but if the car is running that good it almost deserve to pass at that point). Colorado emissions only exist in Denver, and are more wholistic in that they just don't want poor running cars on the road. It's carryover from days when carburetor equipped cars driven by Californians were moving in masses to the beautiful and high altitude Colorado without adjusting the jets, and turning the clean air into a liberal cesspool of smog and smug resembling LA.

f'kin e90post. When I used to test cars, I would have failed you all because I was that guy who actually looked for cats. Yep. All of you. :-)

More of Colorado gets tested now, but yes, it is easy to pass for newer cars. Just need to pass one or the other. For older cars, they run it on a dyno for awhile and use s sniffer and pull statuses . Ive passed the roadside sniffer with no cats by just roiling by in neutral.