Calling all CA Smog experts

[e30pq]

I have an E30 with a 95 M3 motor (S50). I took it to the CA Smog referee to get the engine swap approved and smog tested.

I passed the visual by having all the stock emissions equipment installed.

I failed the sniff test. The inspector suggested that it might be my O2 sensor but his suggestion is that I take it to a BMW tech.

Let me say the car runs good. I don't have any complaints about the way the engine is performing.

I was running the M20 O2 sensor up until now. As I said, the car has an S50 motor, S50 cat and E36 ECU. The M20 O2 sensor could be the part of the problem. I have a new E36 M50/S50 O2 sensor on order.

Here are the results of the smog test:

15 mph HC (PPM) max 85, measured 214 fail
15 mph CO (%) max .50, measured .72 fail
15 mph NO (PPM) max 695, measured 1776 fail

25 mph HC (PPM) max 50, measured 50 pass
25 mph CO (%) max .47, measured .10 pass
25 mph NO (PPM) max 717, measured 40 pass

Specs on the motor:
S50 with about 100k miles on it
540 HFM
24lb injectors
Turner/Conforti software with EWS delete, 540 HFM, 24lb injectors
E36 S50 cat with one O2 sensor
E36 M3 Remus catback exhaust

Any thoughts on what could be causing the results?

[e30pq]

I have an E30 with a 95 M3 motor (S50). I took it to the CA Smog referee to get the engine swap approved and smog tested.

I passed the visual by having all the stock emissions equipment installed.

I failed the sniff test. The inspector suggested that it might be my O2 sensor but his suggestion is that I take it to a BMW tech.

Let me say the car runs good. I don't have any complaints about the way the engine is performing.

I was running the M20 O2 sensor up until now. As I said, the car has an S50 motor, S50 cat and E36 ECU. The M20 O2 sensor could be the part of the problem. I have a new E36 M50/S50 O2 sensor on order.

Here are the results of the smog test:

15 mph HC (PPM) max 85, measured 214 fail
15 mph CO (%) max .50, measured .72 fail
15 mph NO (PPM) max 695, measured 1776 fail

25 mph HC (PPM) max 50, measured 50 pass
25 mph CO (%) max .47, measured .10 pass
25 mph NO (PPM) max 717, measured 40 pass

Specs on the motor:
S50 with about 100k miles on it
540 HFM
24lb injectors
Turner/Conforti software with EWS delete, 540 HFM, 24lb injectors
E36 S50 cat with one O2 sensor
E36 M3 Remus catback exhaust

Any thoughts on what could be causing the results?

[theruss1an1]

I am no smog expect, but my best guess is that the large injectors and the software are making it run too rich. I would swap over the factory s50 DME chip, 17.5lb injectors, and the 3 inch HFM.

-Serge

[e30pq]

Thanks but I'm really looking for a little experience on this one. I'm quick enough to pick up on the obvious. The motor didn't leap into my engine bay on its own.

My M20 had 19lb injectors, M30 AFM, adjustable fuel pressure regulator and Turner Conforti software. It passed smog in that configuration twice.

If anyone has passed similar mods I would be interested in your input or if you failed with similar mods I would also be interested in you input.

[e30sd]

paul

talk to nickdrivesm3. not only is a bmw tech but he is a certified smog tech. i'll see if i can page him to this thread.

[m3maker]

Theres a place here in North Hollywood that charges like 155 or 160 to pass it..in case you dont want to deal with that drama...

[JETninja]

Mine passes with my equipment in the siggy. Last time I took it it failed (don't think they had it hot) 1st test, they changed the Oil and it passed the 2nd test. No problem with visual either. Up in Mission Viejo if your interested in the shop, pm me....

[f4im3]

What are your o2 readings, Nick may want them too. Seems really rich but could be a lean misfire since your nox is so high.

[trioville]

It does sound like the O2 and maybe the cat. Take it to a shop and have them check to see if the O2 is switching properly and also whether the cat needs to be replaced.

[TravisChase]

How old is your cat? Was the cat warmed up before the test was performed? Your NOx (NO) is very high. This is caused by too high of combustion chamber temps (carbon build up, raised compression, too lean, etc.) At 25 mph everything looks ok. I would get the cat really hot and then have them test it. If that does not work maybe think about replacing the cat.

[e30pq]

paul

talk to nickdrivesm3. not only is a bmw tech but he is a certified smog tech. i'll see if i can page him to this thread.

Thanks. I would like his input and possibly his help.

Unfortunately I need to take the car back to the BAR Smog Referee since I started that process.

My goal is to hopefully get the ready to pass without having to un-do some of the mods.

[e30pq]

Theres a place here in North Hollywood that charges like 155 or 160 to pass it..in case you dont want to deal with that drama...

Thanks for the suggestion. Hopefully I won't need to go up to N Hollywood to get this resolved but if I do I appreciate the tip.

[e30pq]

Mine passes with my equipment in the siggy. Last time I took it it failed (don't think they had it hot) 1st test, they changed the Oil and it passed the 2nd test. No problem with visual either. Up in Mission Viejo if your interested in the shop, pm me....


Great feedback. Okay, now I don't feel like my mods are a major barrier to passing smog.

Did the oil change help the smog reading?

[e30pq]

How old is your cat? Was the cat warmed up before the test was performed? Your NOx (NO) is very high. This is caused by too high of combustion chamber temps (carbon build up, raised compression, too lean, etc.) At 25 mph everything looks ok. I would get the cat really hot and then have them test it. If that does not work maybe think about replacing the cat.

Thanks for the input.

I bought the cat used off this board.

One other mod might be the culprit, I have Ignition Solution coils. Could they be firing too hot at low rpm causing it to run lean?

I drove about 30 minutes on the freeway to get to the BAR Smog Referee so the cat should have been hot enough. It probably took them about 30 minutes to get to the roller test.

[e30pq]

It does sound like the O2 and maybe the cat. Take it to a shop and have them check to see if the O2 is switching properly and also whether the cat needs to be replaced.

Good feedback. I will be installing a new O2 sensor.

I will see about having the cat checked as well.

[mrdeezy]

Pm me if you need help.I am in carlsbad,I can do manual dyno testing(without state communications) to see if it its under limits.

[nickdrivesm3]

You're not posting all of your SMOG results. What were the O2 levels? What was the CO2 rating? These are essenial tools to being able to shotgun why your car runs rich with 24lb injectors and the wrong O2 sensor.

[e30pq]

You're not posting all of your SMOG results. What were the O2 levels? What was the CO2 rating? These are essenial tools to being able to shotgun why your car runs rich with 24lb injectors and the wrong O2 sensor.

15mph
2012 rpm
CO2% 14.0
O2% 0.6

25mph
2117 rpm
CO2% 14.7
O2% 0.0

I think that's everything from this report.

[BinhM3]

your cat isnt warmed up, look at high speed your nox and CO is way down, you may want to do a tune up, check cooling system. Have a place check your O2 sensor to see if its lazy.... If you dont want to go through all the trouble just replace the cat, 80% of the time itll pass. Its not the correct way of solving the problem but its like a quick way... most mechanic will just replace the cat, b/c its most profitable and easy to do...

[nickdrivesm3]

PM sent


What are your o2 readings, Nick may want them too. Seems really rich but could be a lean misfire since your nox is so high.

It can't be a LEAN misfire because he has too much CO and not enough O2. He has almost an equal amount of CO and O2 and his CO2 isn't even really that low.

[Em1 For Life]

hc is unburnt gas in the cylinders. So i'd change lil shit like the fuel filter. When i went to state ref last month for my civic I still had a walbro pump when i first tested and when i retested it with the stock fuel pump it was better. You should also lower your timing and heat your cat up before you go test! GOOD LUCK!

[y2kcal]

+1 to binh

got smog check last week and the first run didn't pass. the smog guy said my engine/cat were not hot enough and he asked me drive around while he worked on another car. i drove around for 10 minutes and the number for HC was way down and passed the smog.

[David Aye]

change ur fuel filter, air filter, run some valve cleaner/injector cleaner...

then a few minutes before your car is put on the smog tester, (after she is fully warmed up), drive around at a pretty high rpm (about 4-5k), to really heat up the cats for a good 2 minutes....


should be fine.

[jayhudson]

Threads merged. Please do not cross post in multiple forums.

Thanks - Jay

[brakelate]

I just passed with my S50 doing 3 things

Got the cats Hot Hot Hot

Wired my Auxillary fan to full blast<---once I got on the Test machine.

And ran a bottle of Techron concentrate.

Passed first shot, but it was close.
Seems to work every time.

[Jason C SBB]

0 O2 = running rich.

[Kos-motate139]

I have a sort of similar setup - a 2.8l S52 cammed M52 that I got past BAR testing as well. A bottle of RXP really cleaned up the NOx numbers, and to get HC to pass, I put the stock chip back in. My cat was a junkyard one too, that probably has something to do with it.

[m3luckyoo]

You should be fine after you install the o2 sensor. Try that first and take back for another run- they are free until you pass as long as you take it back to the same place. Do it one part at a time and zero in on the issue instead of doing too many things to try to fix it. You got plenty of time =P Im assuming u have another D/D hehe.

[Zubehor]

I've also had problems trying to pass with these cars (E36 M3s), sometimes its cheaper and easier to just pay someone to pass it.
Now to throw in my 2c.
First off Ive also had the turner chip for euro hfm and 24's on my s50 and the tune on it was crap, way too rich. Ive also read numerous posts on the forum how other people have had the same problem and lost hp/tq when changing to the turner chip for the 24's. Do you have a wideband installed?
Two: definitely get a new/right 02 sensor.
Other then then those two changing the oil, air filter, and spark plugs help the HC numbers quite a bit. I tried to pass an M3 4 months ago, failed at 15mph for high HC, went home changed my oil and retested it and passed, HC's went down 40 points i think.
Also someone recommended I go to a paint store and buy a gallon or two of denatured alcohol. Run your tank almost empty and poor it in. Run the car to get it through and take it to get tested. That should do the trick. Once you pass fill her up with regular gas and drive it for a bit. This is not something you want to do that often because it will eat up your lines.

The list of advice can go forever, i think its easier to just pay $200 and be done with it.
Good luck and post back letting us know how it went.

[Bene36m3]

Im glad i dont live in cali anymore. Now the only things i have to deal with is the bad roads and european car haters.

[RotaryBzzz]

Wired my Auxillary fan to full blast<---once I got on the Test machine.


Did you short the coolant temp switch?
I'm curious why you wired the fan to kick on??

[e30pq]

Thanks for the feedback.

I have a new O2 sensor. I need to install that this weekend once my in-laws leave.

I will post once I test again.

[TH3 Shifty]

this may seem odd to you.. but what spark plugs are you using.. and what gap? This will have an effect on the burn in the cylinder..

[e30pq]

I passed the referee smog test on Friday.

I changed the O2 sensor. This was probably the main cause for not passing the first time.

The other thing I did was get the cat really hot. I drove for about 60 minutes before I got there (mostly at 4,000 rpm).

I also changed my spark plugs and added a bottle of Techron to my gas tank. I figured those wouldn't hurt.

Here are the numbers:

15 mph, 1985 rpm
CO2% 14.8
O2% .1
HC (PPM) Max 85, Ave 21, Meas 20
CO (%) Max .5, Ave .06, Meas .06
NO (PPM) Max 695, Ave 150, Meas 474

25 mph, 2060 rpm
CO2% 14.9
O2% .1
HC (PPM) Max 50, Ave 13, Meas 38
CO (%) Max .47, Ave .05, Meas .15
NO (PPM) Max 717, Ave 136, Meas 700

Thanks for all the feedback and support.

Paul Q