Vehicle Emissions in Jefferson County

[PointBlank82]

Anyone got any advice on passing emissions with modified vehicles in Jefferson, County?

Vehicle #1:
2007 Jeep Grand Cherokee with 3.0L Diesel, AWD
Modifications: Green Diesel "Hot" tune, DPF delete & Pipe
In Arizona I got an immediate pass because they didn't have a dyno for AWD vehicles. Same in LA, not sure about CO.

Vehicle #2:
1985 Jeep CJ7 with swapped in 4.0L from a 1994 Jeep Grand Cherokee
Modifications: Custom five-wire fuel injection from Painless (oxygen sensor, cat converter, etc. still intact)
Condition: Light smoke after 10 minute idle. Passed the sniff test in AZ, but failed visual due to lack of out dated "Air Pulse Injection System" original to the 1985 horrible Carter carb system I threw away after the engine swap. Last summer I pulled an air blower from a 90's era Saturn and installed it in a very prominent location and labeled it "Air Blower". Vehicle has not been registered since I lived in OK in 2012 where they didn't care what I drove. (yes I've moved around a lot).

I really want to get the CJ7 street legal without spending anymore money. It's going to be a lot of fun in CO (lifted, locked and geared). The JGC is my daily driver and if forced, I could bolt the DPF back in, but that would be a major PITA as I'd have to reprogram the ECU and change the oil back to European Low Ash Liquid Gold (TM). The 3.0L runs really clean and doesn't need one (they don't even use them in Europe, only here!).

[Gunner]

Gonna need that dpf pipe put back and all emission stuff for most counties in colorado on the cherokee.

That cj will have more Le away


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[fitz19d]

Wasn't Weld one of the ones that didn't have all the extra junk or was easier? Might look into that.

[Big E3]

Since diesels are not tested in the state-run testing centers and are tested privately, you could call around see what they say. May find one that is less concerned about what equipment isn't installed and more about results of the test. There are many diesel tuner shops that also do testing.

[PointBlank82]

Since diesels are not tested in the state-run testing centers and are tested privately, you could call around see what they say. May find one that is less concerned about what equipment isn't installed and more about results of the test. There are many diesel tuner shops that also do testing.

Excellent suggestion. I wonder how hard it will be to find a tester equipped with a dyno setup for AWD...

[brutal]

I don't think the diesel testers do a dyno.

Visual, sniff test, parts, etc.

Mine passes every time, but I only have a box that is set to "factory" when tested and since it's an older diesel, none of the emissions crap. AFAIK, they don't give two shits about the software tunes, just that it passes the numbers.

That said, I think it could be difficult to find one that will give you a pass if you're missing factory equipment like DPF. Their testing license is on the line and they have to meet the State/County reqs.

[ray1970]

Like others, I think you might have issues getting the diesel to pass.

The Jeep might be easier because you have to meet 1985 emissions standards which I imagine the newer engine will likely meet. If the "light smoke" is oil burning, I might also suggest changing over to a full synthetic oil. Since full synthetic isn't hydrocarbon based it won't make visible smoke when it burns.

[PointBlank82]

Like others, I think you might have issues getting the diesel to pass.

The Jeep might be easier because you have to meet 1985 emissions standards which I imagine the newer engine will likely meet. If the "light smoke" is oil burning, I might also suggest changing over to a full synthetic oil. Since full synthetic isn't hydrocarbon based it won't make visible smoke when it burns.

Never heard that about synthetic oil. I have some concerns about making that switch given the age of the engine and possibly dissolving varnish. I finally got it all to stop leaking a couple years ago, hate to go through that again.

I did read on the DMV web page that vehicles 32 years and older can be registered as "collectors vehicles" if they're driven under 4500 miles per year... and then only get tested once every 5 years. hmmm might be worth trying the synthetic option for the test and just replacing before it runs too long.

[Great-Kazoo]

Wasn't Weld one of the ones that didn't have all the extra junk or was easier? Might look into that.

Negative. All counties doing emissions are the same.

Never heard that about synthetic oil. I have some concerns about making that switch given the age of the engine and possibly dissolving varnish. I finally got it all to stop leaking a couple years ago, hate to go through that again.

I did read on the DMV web page that vehicles 32 years and older can be registered as "collectors vehicles" if they're driven under 4500 miles per year... and then only get tested once every 5 years. hmmm might be worth trying the synthetic option for the test and just replacing before it runs too long.

I suggest you replace the fuel cap, they do a pressure test on it. If it fails, you have to repeat the test.

[ray1970]

I suggest you replace the fuel cap, they do a pressure test on it. If it fails, you have to repeat the test.

Are they still doing the cap test? I haven't actually been to one of the emissions places in a while but I heard they no longer test the cap and as long as you don't have any evap codes when they hook up to the vehicle then you're good to go.

The place by my house was always pretty lenient on the gas cap. I had one fail once but they went ahead and passed me but told me I need to go get a new one. Never had any P0440 or 442 codes so I figured they probably just didn't know what they were doing. Went back a couple of years later without ever replacing that cap and it tested good.

Once the OP finally gets all this stuff straightened out I highly recommend making sure to drive through the roadside emissions things so he doesn't have to make a trip to those horrible testing stations.