Tips to pass diesel emissions

[Me78569]

Yet another topic that needs to be written up into an article for those of us unlucky enough to have emissions tests.  please add any tips or correct anything I put in.

 

 

Up until this point I have had a pretty much stock truck.  I turned the box off and passed without issues.  In el paso county Colorado Springs we are required to pass a couple of tests.

 

Snap test at 35mph and 55mph I think with opacity of %30 or less. ( what does %30 opacity actually look like) 

 

A snap test means that the person will go from idle to %100 throttle and watch for smoke output.

 

What I wanted to do is put together some things you can do to help pass with your diesel.  in my case a 24v with 100 hp injectors, quadzilla adr, and a he351ve.    My setup should pass without much issue provided I turn the tuner off, however some guys might not be able to pass.

 

Lets start with the basics

-tuner off

-Smarty that can do half power mode.

-throw oem injectors in

-Fix any boost tests

-ensure your map isn't stuck reading high

-run no additives, no 2 stroke.

-new air filter

-ensure that the truck is up to temp.

 

 

Beyond the basics,

 

So lets start with timing,  Does timing tuner levels help or hurt smoke levels when talking about passing emissions?

 

Another thought I had was to disabled TC lockup to help pass emissions if they do a snap test on the dyno.  This would decrease spool time, decrease load, and thus decrease smoke.  

 

In conjuction with that depending on how they do the emissions tests you could disabled OD, which depending on the speed they do snap tests would keep rpms up rather than having to deal with the low rpm load found at 45-55 mph while in OD.

 

If you wanted to get pretty technical you could install a voltage clamp on the map sensor wire, to 5ish psi,  to limit the boost the ecm is going to see, thus limiting the fuel the ecm will depend.  

 

Thoughts?

[Mopar1973Man]

The biggest thing is the visual inspection looking for modification. Loooking for wire taps, other plug in mods like my high idle and MPG fooler would cause a fail. So the first thing is to make the truck visually stock looking. This means in the cab too. So if you got a Edge Juice module hanging on the A-pillar you most likely going to fail.

 

You might want to also check for any existing error codes even if the check engine light is OFF. There is some code that will not trip a light but might impact the ability of making a passing grade. This doesn't mean erasing the codes and hoping they stay away. This means reading the codes writing them down. Then erase the codes. Then go for a nice 10-20 mile ride to get full warmed up and allow the truck go through cycle. Then check the codes again and deal with the second set if any. The first set will give you a clue to intermittent issues that might still give problems later. But be sure that all codes are clear and repaired before testing.

 

Might be also a good thing to do a tune up fo changing fuel and air filters. It couldn't hurt.

[IBMobile]

The biggest thing is the visual inspection looking for modification. Loooking for wire taps, other plug in mods like my high idle and MPG fooler would cause a fail. So the first thing is to make the truck visually stock looking. This means in the cab too. So if you got a Edge Juice module hanging on the A-pillar you most likely going to fail.

 

You might want to also check for any existing error codes even if the check engine light is OFF. There is some code that will not trip a light but might impact the ability of making a passing grade. This doesn't mean erasing the codes and hoping they stay away. This means reading the codes writing them down. Then erase the codes. Then go for a nice 10-20 mile ride to get full warmed up and allow the truck go through cycle. Then check the codes again and deal with the second set if any. The first set will give you a clue to intermittent issues that might still give problems later. But be sure that all codes are clear and repaired before testing.

 

Might be also a good thing to do a tune up fo changing fuel and air filters. It couldn't hurt.

Every thing that Mike said is true for California and no smoke other than start up. The inspector plugs in to the OBD II port and check for codes and the monitor readiness. Not all of California gets SMOG tested. It's done by counties and in some counties it's done by zip code. With every state having their own test parameters, if any, makes it difficult to formulate protocol for compliance. It may be best to find out what the inspectors in your state are looking for and adjust to that or get yourself a friend in a state that doesn't require SMOG testing yet, and register it there. 

[AH64ID]

Some additives may help reduce smoke so if you smoke on a DIY snap test then try an additive or two.

Gauges and monitors will not make you fail, but if it looks like a tuner it may be a different story.

As for codes it may take 3-5 run cycles, that's cold-hot as one cycle, to get OBDII monitors ready so you can't clear codes on the way to the test.

Do a couple of WOT runs to clean out the pipes so you area failing the snap test from residual soot being blown out on a snap test.

[Mopar1973Man]

Some additives may help reduce smoke so if you smoke on a DIY snap test then try an additive or two.

 

I would imagine that cetane boosters would aid in cleaning up the smoke.

 

As for codes it may take 3-5 run cycles, that's cold-hot as one cycle, to get OBDII monitors ready so you can't clear codes on the way to the test.

 

Very true. You need to show readiness for OBD testing. I know my ScanGauge II shows this information during code scanning with either NOT READY or READY. Each vehicle might be a bit different in getting a READY status.

 

Do a couple of WOT runs to clean out the pipes so you area failing the snap test from residual soot being blown out on a snap test.

 

 

Another way is to hitch up a trailer and get some nice and hot pyrometer temperatures going to cook the exhaust system clean also cook the injectors clean as well. Might help clean up some of the smoking issues.

[JAG1]

I would imagine that cetane boosters would aid in cleaning up the smoke.

 

 

Very true. You need to show readiness for OBD testing. I know my ScanGauge II shows this information during code scanning with either NOT READY or READY. Each vehicle might be a bit different in getting a READY status.

 

 

Another way is to hitch up a trailer and get some nice and hot pyrometer temperatures going to cook the exhaust system clean also cook the injectors clean as well. Might help clean up some of the smoking issues.

Is that why there's a NO SMOKIN sign on your tail pipe Mike?

[Mopar1973Man]

Don't even go there. I should write "Got Soot?" on the bumper corner chrome and take a picture...

[JAG1]

Hey, that would be a good brand name GOT SOOT?

Should have on back bumper, 'EPA Inspector' Ahhh such off topic silliness but it won't delete.

[Dave3500]

Don't even go there. I should write "Got Soot?" on the bumper corner chrome and take a picture...

LOL, you guys need to be having good clean fun? Would BioDiesel help?

[duesman]

I just change my motor oil and check my air filter my truck is totally stock 2002 154000 miles opacity last time 1.3 same thing time before I livein ct

[Mopar1973Man]

LOL, you guys need to be having good clean fun? Would BioDiesel help?

 

No. It will make things worse. BioDiesel is high cetane and lower in BTU's so you typically end up with lower MPG's. The reduction is based on how high the biodiesel mixture is. 2% typically is very low reduction of MPG being its a majority of petroleum. Now 100% has the lowest MPG numbers as well as BTU ratings. High cetane is only required in the winter time to promote starting in cold climates. The only time high cetane is required other than winter is racing. When you twisting up to 4K RPM's you need a fuel to burn fast enough to keep up. Typically daily drivers never see those conditions. Also Biofuel tends to product more emissions than petroleum based fuels. There is a post by Wild & Free about biodiesel emissions.

 

Low smoke is based on warmer intake temps, smaller injectors and quick spooling turbos like the HY35W. Black smoke is because of fuel droplets that are too big and there isn't enough heat to convert the liquid to vapor. This why the 190*F thermostat is desired more so over the 180*F is the heat to aid in conversion. Remember liquid fuel will NOT burn. Only the vapor can burn.

 

Also there is also a point where too much fuel is injected with too little boost (lack of air vs fuel). This is more or less a need for quick spooling turbo or adding lag to your fuel map to allow the turbo to light. This is where most make mistakes and upgrade turbos and get so big of a turbo that can never light it till they are driving at illegal speeds. Cowboy and Me78569 are working on VGT controller that is stand alone. This would change the game quickly. But again it's not a stock turbo so it would fail the inspection.

[cbrew]

in my county, the owner of the truck is at the controls during the snap test, so i just learned to rolling in the throttle, that short delay seemed to make all the difference with passing the snap test with my old 12v.

[TFaoro]

Nick - To your timing comment.

At slower RPMs and no boost lower timing BTDC will create less smoke.

 

If anyone in my "general" area is in need you are free to use my smarty.