Smog woes - HC

[Johal E32]

Cataclean might be worth a shot, a buddy of mine has used CRC Guaranteed 2 Pass with successful results on his 1997 M3 that initially failed smog. I would assume Cataclean needs to go through a tank of gas before it is ready for smog, so keep that in mind (since you have expired tags).

[Green95M3]

Any update, GetOuttaMyWay?

I'm basically in the same boat with my '95 M3. High HC's @15 mph.

Thus far, I have done the following:
1. Replaced grossly leaking valve cover
2. 6 new coils
3. 6 new plugs
4. New Bosch O2 sensor

Compression is great on all cylinders. The injectors are good. Smoke tested, no vacuum leaks.

Today's failure was vastly worse than previous tests, 199 measured vs. mid 80's previously. This is a different station, which could be part of the problem. Rear tires @ 40 psi.

I have Magnaflow cats which were installed about 30k ago. I'm starting to think those might be the problem.

Please give us an update when you can.

Thanks

[bmwstephen]

how long did you run the car before testing, and how long did it rest for before running the test? and what sort of plugs did you use?

Any update, GetOuttaMyWay?

I'm basically in the same boat with my '95 M3. High HC's @15 mph.

Thus far, I have done the following:
1. Replaced grossly leaking valve cover
2. 6 new coils
3. 6 new plugs
4. New Bosch O2 sensor

Compression is great on all cylinders. The injectors are good. Smoke tested, no vacuum leaks.

Today's failure was vastly worse than previous tests, 199 measured vs. mid 80's previously. This is a different station, which could be part of the problem. Rear tires @ 40 psi.

I have Magnaflow cats which were installed about 30k ago. I'm starting to think those might be the problem.

Please give us an update when you can.

Thanks

[nick325xit 5spd]

Any update, GetOuttaMyWay?

I'm basically in the same boat with my '95 M3. High HC's @15 mph.

Thus far, I have done the following:
1. Replaced grossly leaking valve cover
2. 6 new coils
3. 6 new plugs
4. New Bosch O2 sensor

Compression is great on all cylinders. The injectors are good. Smoke tested, no vacuum leaks.

Today's failure was vastly worse than previous tests, 199 measured vs. mid 80's previously. This is a different station, which could be part of the problem. Rear tires @ 40 psi.

I have Magnaflow cats which were installed about 30k ago. I'm starting to think those might be the problem.

Please give us an update when you can.

Thanks

Magnaflow cats are garbage, 30k on them is a miracle.

[GetOuttaMyWay]

I passed! Thanks everyone here for your help. Green95M3- It's hard to say what got me in the clear because I did a ton of work in the last year (cleaned and rebuilt injectors, new fuel filter, new coil boots, spark plugs, replaced a few lifters, re-timed the cams, rebuilt the vanos... god probably other stuff too). Also my car is OBD2 and I'm assuming yours is OBD1. But here's what got me in the ballpark and ultimately got me passed:

- The O2 sensors (new) were only reading 9v on the heater circuit. I'm not sure if OBD1 uses the 4 wire sensor. The 4 wire cars need the sensors to be at the right operating temp to read correctly, at only 9v instead of 12-14v bat voltage they weren't reading right. That was fixed just by literally pulling the heater circuit relay and plugging it back in, there must have been a bad connection there. My numbers went way down after that, but still not passing. After I found that I went in and pulled every relay and fuse and sprayed them with contact cleaner, even though they all visibly looked great. After that I did:

- I ran that CataClean stuff. Honestly not sure if it did anything, or it was other variables (below).
- I put in a heavy mix of E85 (probably close to 60%). I strongly suspect this might have been a big factor in passing.

With the above, I did a pre-test and it passed but barely. For the final (maybe 30 mins later) test the tech ran it on the dyno for a good while and got it really hot and the numbers were much lower than the pre-test and I passed.

Hope this helps... I would say if everything is in tune, blend in some e85 and ask the tech to run it on the dyno for at least 3-5 mins. I took the car for a good long rip before the test, but by the time they do their admin work and check the codes, visual, etc.. I think the cats just cool down too much even if you leave it idling.

I should look at the pre-test vs final because the only variable between the two was a longer warm up on the dyno. That should tell us how much of a difference that made...

[nick325xit 5spd]

Congrats!!!!!

[ax77]

I passed! Thanks everyone here for your help. Green95M3- It's hard to say what got me in the clear because I did a ton of work in the last year (cleaned and rebuilt injectors, new fuel filter, new coil boots, spark plugs, replaced a few lifters, re-timed the cams, rebuilt the vanos... god probably other stuff too). Also my car is OBD2 and I'm assuming yours is OBD1. But here's what got me in the ballpark and ultimately got me passed:

- The O2 sensors (new) were only reading 9v on the heater circuit. I'm not sure if OBD1 uses the 4 wire sensor. The 4 wire cars need the sensors to be at the right operating temp to read correctly, at only 9v instead of 12-14v bat voltage they weren't reading right. That was fixed just by literally pulling the heater circuit relay and plugging it back in, there must have been a bad connection there. My numbers went way down after that, but still not passing. After I found that I went in and pulled every relay and fuse and sprayed them with contact cleaner, even though they all visibly looked great. After that I did:

- I ran that CataClean stuff. Honestly not sure if it did anything, or it was other variables (below).
- I put in a heavy mix of E85 (probably close to 60%). I strongly suspect this might have been a big factor in passing.

With the above, I did a pre-test and it passed but barely. For the final (maybe 30 mins later) test the tech ran it on the dyno for a good while and got it really hot and the numbers were much lower than the pre-test and I passed.

Hope this helps... I would say if everything is in tune, blend in some e85 and ask the tech to run it on the dyno for at least 3-5 mins. I took the car for a good long rip before the test, but by the time they do their admin work and check the codes, visual, etc.. I think the cats just cool down too much even if you leave it idling.

I should look at the pre-test vs final because the only variable between the two was a longer warm up on the dyno. That should tell us how much of a difference that made...

how did your numbers change with the E85?

[shogun]

Would be interesting to know how the numbers changed with the E85.

one more point to consider, what I have read: my 02/98 M3 has a DME Siemens MS41.1.The Siemens DME has the adaption values of the old defective O2 sensors stored. These adaption values cannot be deleted like on the Bosch 3.31 DME by disconnecting the battery for some time, and then drive the car 30-50 miles to get the new adaption values.
On the Siemens the adaption values must be flashed with a diagnosis tool. Not flashing causes bad engine running, as the old O2 sensor values are slower and weaker. When the Siemens DME is flashed, the new O2 sensors adaption values will be adapted much faster, Otherwise it takes a much longer time till this happens and you have to drive longer to get it adapted to the new sensors.
===================
If the DME is not flashed after changing the O2 sensors, how long will it take (in miles) till the DME will adapt to the new sensors?

[nick325xit 5spd]

Would be interesting to know how the numbers changed with the E85.

one more point to consider, what I have read: my 02/98 M3 has a DME Siemens MS41.1.The Siemens DME has the adaption values of the old defective O2 sensors stored. These adaption values cannot be deleted like on the Bosch 3.31 DME by disconnecting the battery for some time, and then drive the car 30-50 miles to get the new adaption values.
On the Siemens the adaption values must be flashed with a diagnosis tool. Not flashing causes bad engine running, as the old O2 sensor values are slower and weaker. When the Siemens DME is flashed, the new O2 sensors adaption values will be adapted much faster, Otherwise it takes a much longer time till this happens and you have to drive longer to get it adapted to the new sensors.
===================
If the DME is not flashed after changing the O2 sensors, how long will it take (in miles) till the DME will adapt to the new sensors?

If the car wasn't adapted off the range so far that it ran poorly, it doesn't take that long to re-adapt. A good drive with a solid highway run should do it.

[shogun]

Thanks for the explanations about the adaption time of the DME Siemens MS41.1. with new O2 sensors, that means, actually no need to flash with a diagnosis tool.

[nick325xit 5spd]

Thanks for the explanations about the adaption time of the DME Siemens MS41.1. with new O2 sensors, that means, actually no need to flash with a diagnosis tool.

This assumes that you haven't reached an adaptation limit. due to some other problem.

That's where things get sticky - but that's usually not going to be an O2 specific issue. As an example, if you have a misfire due to a bad injector, the unburnt fuel will read as rich at the O2. Even though the car is misfiring because it's too lean, the DME thinks it's rich and will keep pulling fuel making every other cylinder run like garbage too. Once you've pegged the adaptation limit here, it's difficult for the DME to escape that loop by itself. You may well need to reset the adaptations in that case even after fixing the issue. I cite this example because I've actually experienced it.

[importbanana]

How do you reset the adaptions? Can they be reset in INPA? Where in INPA? Or is other software necessary, if yes, which one?

[AJLM34A]

Rom Raider is a great software for tuning the ECU on the obd2 M52/S52 engines. It's quite inexpensive, needing just the correct USB to OBD adapter and a flashing program.

https://sites.google.com/site/openms...with-romraider

^^^^^^^^^^^^^^^^^^ THIS

For a few hundred dollars; refurbished Windows 7 laptop(with an SSD), a usb to ODB2/ADS cable with the proper chip, buy the MS41 flash tool and donate to RomRaider everyone can be tuning their own cars; EWS deletes, SAP delete, turning off irrelevant DTCs(diagnostic trouble codes).

How do you reset the adaptions? Can they be reset in INPA? Where in INPA? Or is other software necessary, if yes, which one?

I reset my adaption values on my HPDE car the day before a track event using the MS41 flash tool. If I have to clear a CEL, I just use my cheap ODB2 scanner but it really just turns off the light. If I hook up my laptop with DIS or my laptop with RR & MS41 flash and read codes, they are still present.
MS41 flash 2313.PNGMS41 flash 213.PNGMS41 flash 23.PNG