Emissions test mystery

This question relates to the 2002 Dodge Ram conversion van I looked at today for possible purchase, for which I posted the “brown transmission fluid” question. To recap, the van has 110k miles, with a 5.2L V8 engine, and I just ran a Carfax report. The vehicle was purchased new in 2003, has had only one owner, and has lived in New Hampshire all its life.

This question is about emissions test failures. Carfax reports that the vehicle failed an emissions test in 2007 at 52k miles. It passed the next test about 90 days later, and passed the next test about 10 months later. It failed the next test in 2009 at 75k, then passed another 2 subsequent tests.

My questions are (1) Why would it fail emissions tests at those relatively young ages, (2) What repairs would the owner have had to make, and (3) With the dominant pattern being a failed test after every 2 passed tests, is the van getting ready to fail its next test?

By the way, all emissions tests were done in Merrimack County, NH, if that matters.

It’s very hard to guess about emissions test failures…You need to see the test reports to see WHY it failed…It could be something very simple like the van was not properly warmed up when it was tested…5.2L, that’s the venerable 318 engine, Chrysler’s workhorse for almost 50 years…They are rock-solid and will run forever…I would not be too worried about the test failures…But you can use that as a bargaining point…Between the test failures and the nasty tranny fluid, this van should sell at a deep discount under “Blue Book” …

If the owner had any brains, he would have the tranny fluid flushed and a fresh emissions test performed to smooth the sale…

Thanks, Caddyman. Good to know the engine is venerable, despite an expected 15 mpg fuel appetite!

I will add the emissions test failures to the growing list of bargaining chips…

As Caddyman said, it’s impossible to guess about emissions failures. I can tell you, however, two things:

  1. NH bases their emissions tests on OBD downloads. If your CEL is clear and you have no codes, you’re good to go. We used to use tailpipe snifers, but no longer.

  2. don’t use Carfax as definitive information. Their information is not accurate enough to be relied upon.

Thanks, mountainbike. Did not know that about NH emissions tests. I’m in MA, though, and I think we do still use sniffers here.

Carfax may not be correct, but in this case I may be able to use it to beat down the price a bit…

The only people who can actually figure out the Massachusetts Emissions Test are the people who make a living performing the “test”…The rest of us just drive in and hope for the best, which usually happens…

Sometimes all it takes to move a car from fail to pass is to replace the air filter or the fuel cap. Past emissions test failures doesn’t necessarily mean the car is defective. It could have been something very minor. At least in Calif that’s my experience.

Before I go for an emissions test (every two years) just before I always put in a new air filter, and make sure the gas cap is sealing correctly. If the car hasn’t had the spark plugs changed and the ignition timing set in the past 4 years, I do that too. Then I drive the car in the most convulted slow moving path to get to the testing site, so it is fully warmed up when I arrive. I also try to schedule it for a warm dry day.

Mass is somewhat like Calif…Some cars get this kind of test, others get that kind of test…Still others get no test at all…Trucks, well they get a different test and Diesel trucks get something that looks like a test but actually tests very little…We all pay for a slip of paper that says we took a test and 97% of the time we passed the test we just took…Air quality where we live pretty much stays the same whether we passed the test or not…Somebody gets $35…

Honestly, if a vehicle shows that it failed emissions tests, that’s a huge red flag that the vehicle most likely wasn’t properly maintained by its previous owners.

It takes a lot to fail most tests, and if there’s something wrong with the car to that extent, then chances are the CEL is lit up, and staring the driver in the face long before they get to the testing place.

Probably something as simple as needing new plugs, wires, and an oil change to pass, but why didn’t they do that before going to the shop? Either laziness or cheapness.

Do you really want to own a vehicle that was previously owned by either a cheap person or a lazy person?


I dont think its a big deal, I have failed more then one test in the past and it is usually something dumb. Back in the day of Carbs if you sat on line to long (this was in NJ where the state had free inspections, but sometimes the lines were over an hour long), you would be rich and fail. On the new system you can fail for a gas cap and its emissions… The 318 is not exactly the cleanest motor in the world to start with, and it has far from what would call an advanced fuel injection system (is it stil thottle body or is it MPI)… IN any case it is probably running the edge of clean and dirty even when running right. Not a big deal, the trans is a much bigger deal…