Smog Test Result Comparison
 

Hello -

I got my California smog test in August 2007 :

http://ecomodder.com/forum/attachmen...1&d=1232588077

As stated in another thread, my car passed with great numbers for HC and CO pollution (below the average !), but the NOx was higher than normal. I did have the HAI (Hot Air Intake) online, so maybe this is an effect of the (mild) lean-burn. I think the IAT was running over 125 degrees F when I got the test.

My wife just got her 2003 Civic Coupe tested :

http://ecomodder.com/forum/attachmen...1&d=1232588077

Other than the numbers for the NOx, which are still well within legal limits, my old SW2 is holding up well. My wife's Honda is bone stock, but is also pushing the NOx above average. For each test you can see that the maximum allowed emissions are a wee bit lower across the board. I expected a bigger difference between 1999 and 2003, but I am actually happier that my 4 year older car is being held to close to the same standard. Maybe the maximum emissions is a function of the displacement of the cars. I have a 1.9 liter engine, and she has a 1.7 liter engine.

CarloSW2

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Thanks for posting.

( I can't see your images though . )

I'll have to post my results too.
I would love to see more peoples results, and find out what mods help / harm our emissions score.

Cd -

Thanks for telling me. I had a broken Internet connection last night, so I think I lost the image download during the posting.

If I *really* had my act together, I would do some smog testing with gizmos on and off to see what happens, just like you say.

CarloSW2

They're both OBD-2... They should be held to nearly the same standard of emissions requirements... obviously, engine size makes a difference, but probably not to a huge extent when you're only talking about .2 liters of displacement.

I'm not suprised that your WAI raised NOx. NOx is created by high combustion temps and you took some of the cooling that is supplied to the cylinder away.

Hello -

Update on my emissions. I passed, but my NOx is really high, so I am :( . I kept the WAI for this new test because I wanted to make the comparison test otherwise equal between 2007 and 2009.

http://ecomodder.com/forum/member-cf...d-clean-my.jpg

http://ecomodder.com/forum/member-cf...ot-looking.jpg

I figured out that the 25 MPH test was done in different gears. The 2007 test was done in 3rd gear, but the 2009 test was done in 2nd gear. I made a spreadsheet that "cross-derived" the NOx emissions for a better comparison :

http://ecomodder.com/forum/member-cf...aking-into.jpg

Essentially, my NOx jumped 400% from two years and 39K miles ago. Based on the above trend, I can tell that my (25 MPH) NOx will be non-compliant within the next 6 months.

My HC PPM is also way up, but I think that if I solve my NOx, I will solve my HC.

My one year goal will be N-fold :

1 - Get the car tuned up. It's mostly just been regular maintenance and as-needed repairs (radiator and water pump). I do have a P0410 error code (secondary air injection pump), but I think that plays only a small (engine warm-up) part of emissions.

2 - Do an oil analysis (pending).

3 - Retest with and without the WAI. I talked to the smog dude and I can pay him to do a non-DMV smog test.

4 - Maybe do an Auto-Rx style treatment. I have some stuff called XcelPlus "Engine Protection" and "Upper Cylinder Treatment". It's been sitting in my garage for a few years. If I can verify that it's chemically stable, I will probably try it out.

5 - Maybe get a new set of spark plug wires. I am positive that I have my original wires. I want either OEM or Magnecor.

I'm hoping I'm not approaching an engine rebuild. I don't think I can't justify keeping my SW2 if I have to do a rebuild, but the emotional part of me wants to "find a way".

CarloSW2

Don't worry about an engine rebuild. We have ways (legal ones!) of making you pass smog. ;)

I don't think your HC levels are really that high. NOx is through the roof, so an interblag search says to check EGR, ignition timing, and O2 operation, which you should be able to do on your own w/ a service manual and a DMM. If you have a SG, maybe check ignition timing w/ and w/o the WAI (on the safe side, reset the ECU and you take the WAI off, although I'm not sure if that needs to be done w/ OBD-II cars) to see if there's any change.

...And stay away from that "upper cylinder treatment" snake oil... A good tune-up should bring the levels closer to where they should be. Pulling the WAI will probably drop the NOx and raise the HC/CO a little.

-soD

some_other_dave -

Ok. I'm posting the same results onto saturnfans because theyz knowz mee Zaturn :

California Smog Test Results.. (Look at post #7)

The first thing I am going to do is get new ignition wires. I am 80% sure I have the originals.

CarloSW2

I'll have to get some images up with my own results.

Can we get someone with a hybrid, or a PZEV to post their results ? I'd really like to see how we all compare.

Not to divert the topic here, but will a grille block lead to 'lean-burn' and higher emissions results, since the engine stays warmer ?

If so, It's coming off.

Higher engine temps will lead to higher NOx emissions. The same thing goes for lean burn. I don't know if higher engine temps will cause lean burn however. The computer may actually enrich the mixture to try and bring temps down.

Higher in cylinder temps (lean ratio, timing too advanced) lead to excessive NOx formation. I'm pretty sure intake temps can't get hot enough to directly influence this w/o the front end of the car melting off.

ConnClark -

I thought cooling was being managed by the on/off of the electric fan. Doesn't the 02 sensor rule, aka the magic 14.7 AFR (Air/Fuel Ratio), aka closed-loop operation? I know it's more complicated than that, but I think this captures the majority of driving conditions, especially because of the way we drive as Ecomodders.

I agree with roflwaffle that a WAI is not "lean burn" per se. I liken it to driving in Death Valley. Less oxygen per volume of air, so less fuel per volume of air (right?!?!?!). I would claim we are simulating operation in an "extreme zone" of the ECU/PCM. This would contribute to the different reactions by different cars. Depending on how the ECU/PCM was programmed, the engine would like/dislike the WAI.

Maybe this discussion deserves it's own thread ("Does a WAI/HAI increase emissions?"). Same for a grille block.

CarloSW2

Carlos - I think what Clark is trying to say there, is that depending on the situation, your ECU may periodically dump fuel to cool down the pistons, if the ECU thinks that you're running too hot for too long a time. You'd have to monitor/record real-time AFR to figure that out though... or look for a spike in injector duty.

This seems plausible, because dumping fuel is a common way to cool internals in an engine (wasteful, but it works faster than waiting for the radiator to do it.)

Maybe the WAI in combination with the grille block puts you right on the line, and it's possible that you're going over the ECU's "safe limit" once in awhile, and it might be dumping fuel thinking that you're heading for catastrophe, as a way to cool it down and prevent meltdown.

You might consider watching your temps, O2 output, and injector pulsewidth with something that you can download a timed map of them, and compare the signals, looking for spikes in each, and how the signals correspond with one another. You just might find where your "sweet spot" for temperature is, then you can make a CAI/HAI hybrid that will allow you to maintain a given temp more accurately, keeping you on the threshold, but not "in the house", so to speak.

Christ -

I have a real-time digital AFR, so I can see the 02 sensor in action (but no data logging). Once it's warmed up, it almost never goes richer than 14.5 at any time. If anything, I see the ECU/PCM trying to "cheat lean". I often see it go into the mid 15s before popping back to 14.7 +-0.2 oscillation. I use the SG to monitor coolant and IAT, but I can't see injector pulsewidth. I don't know how to interpret the ignition timing parameter (IGN).

I think I understand what ConnClark is getting at, but I am trying to make the distinction that I am not driving normally. I am attempting to drive like an Ecomodder/Hypermiler, keeping the load on my engine as low as possible. This is why I think closed-loop operation dominates my driving. I think the only time I put the car under heavy load is when I accelerate to merge onto the freeway, or under emergency avoidance. There is only one other "high load" condition where I drive up a 4% grade the last mile to my house. I almost always run the electric fan (I have a manual override on/off switch).

CarloSW2

Ok, I just thought I'd clarify and add a few points to it.

It couldn't hurt to "push the limit" a little bit, and find the optimal operating temp for your engine, optimal intake temp, etc... and then find some combination that satisfies them.

Good luck!

Sorry for diverting this thread .

Back on topic ?
...please ?

I'll post my results when I get around to it.

http://farm3.static.flickr.com/2509/...ca23317e65.jpg

http://farm3.static.flickr.com/2651/...cc0a431dd0.jpg

This in no particular order, and my latest results are misplaced.
Let me know if the images are too small.

So I had the impression that hybrid owners had to do a seperate emissions test, because the motor doesn't kick in till later. Is this true ?

Cd -

In your case, the 15 MPH and 25 MPH tests appear to keep the engine running. Because the car is connected to the OBDII port, I'll bet they can signal a hybrid to keep it's engine running anyway (that's what I'd do).

PS - It would be nice to know the date, mileage, model, and your of your car for the tests you posted.

CarloSW2

Whuups ! Sorry.
I wanted to post something useful, and in my haste, I forgot the most important information -
The tests are from my 1993 Honda Civic DX.
The car is a Texas car, and all testing is done here in Texas.

When I have more time ( I'm moving ) I'll try and clean up my posting a little bit. I'll add dates, as well as mileage then as well.

What I would really love to see here would be an emissions test result from someone driving on pure biodiesel !

Cd -

Assuming one exists, I'd like to see any 1999 1.8L Diesel. The reason is, I want to see the compliance Max and Averages requirements of a 1999 diesel at approximately the same displacement. Even a Euro-test would be cool for the sake of comparison.

CarloSW2

See graph on attached link:
Biodiesel as a Transportation Fuel

I have seen this one in more than a few books.

So I just passed smog with "flying colors." Here is the result:

http://ecomodder.com/forum/attachmen...1&d=1409185975

Thing is, they didn't spin the wheels on the dynometer and they didn't give me any readings for NOx. I heard them rev the car up to what sounded like 1500 rpm and 2500 rpm, but not in gear.

I called back to double check that I was not missing a data sheet. They said that's all I'll need. That I pass and I can send in my info.

What's up with that?

Anyone else have that experience?

Another comparison
 

I just passed CA SMOG. Here is my data. Not bad for an 18 year old CAT, huh?

http://ecomodder.com/forum/attachmen...1&d=1471986714

Maybe this is just a rumor, but I read somewhere that a California car that reads high in the sniffer test will get sent to a STAR station the next time around. My old MR2 Spyder certainly did. You would want to remove the warm air intake for smogging the car to reduce the NOx if that rumor is true. Actually you'd want to remove it anyways so that you don't risk failing if your cat is old.

I think the Star requirement might be triggered by age of the vehicle. I have needed a star facility since my 2012 test. I had to remove my XL brake booster canister and my WAI. They let me keep the grill blocking, but I maybe should have removed it for the sake of engine heat and higher possible NOx readings. I cleaned and gapped the OEM spark plugs and swapped them in before the test.