Check engine light and emissions testing

[pickenup]

In hope of helping other avoid having to go through what I just did, I will relate my experience over 2 months.

My check engine light was on, and like most, I believed that my vehicle would fail the emissions test because of it. It has been on every since I bought it over a decade ago. It always passes emissions with flying colors.

Anyway, since they passed a new law in 2015, I was under the impression that it would fail because the check engine light was on. I had done all the routine maintenance that you do anyway. Plugs, filters (including fuel filter) etc. I used Sea Foam in the vacuum lines, and BG 44K in the fuel. I waited until just before I had it tested to change the oil, in case any junk from those cleaners fell in the oil.

I then took it to a parts store because they will do a OBD II check. Well needless to say, they recommended this and that. (upon recommendations from 2 different auto parts store) after cleaning the mass flow air sensor, changing all three O2 sensors, smoke testing for vacuum leaks, and a bunch of other stuff, I took it to another shop.

They recommended changing out the "brain" at over $700. I declined, knowing that I had already spent more $$ than required for the "waiver" the emission place gives you if you spend enough $$.

I called the emission phone number to see what the procedure was to get a waiver. She asked what year my vehicle was, I told her it was a 1996. She said the law only applies to (now don't quote me here, because when I heard this I was SHOCKED) she said the law only applies to "something like" vehicles 2006 or 2008 or NEWER.

Here I was, for 2 months worrying about getting that damn check engine light to go off, changing parts, (have you ever done the "drive cycle" to get the check engine light to go off after replacing some part?) and everything else, only to find out it doesn't matter.

So I went to the emission testing center on the second to last day before I would be charged another $25 for being late getting plates (end of grace period) and had it tested. WITH THE CHECK ENGINE LIGHT BLARING AWAY. I wrote the check, handed it to the tech, and asked if we needed to call a supervisor? He said, "nope, it passed, and you are good to go."

Don't get me wrong, I want my vehicle to run as good as it can, and am still working on that check engine light. But don't expect an auto parts store, or a vehicle repair center to tell you this information. Their job is to sell you parts, or repair you vehicle, NOT to tell you that you don't need anything because your check engine light is on. Unethical maybe a little, but business is business?

[DenverGP]

Glad to hear it passed, even with the check-engine light.

My son had to get his rather heavily modified car tested with a check-engine light on due to a thermostat warning (was very slow to warm up in winter due to running a cooler than normal thermostat and an larger than normal radiator, so always threw a P0128).

Curious, whats the code or codes that are stored? Based on your description of MAF, O2 sensor and vac leaks I'm guessing a code indicating a lean condition (P0171 or P0174)? Or maybe a P1133/P1139 Insufficent switching code?

[ray1970]

I will try and avoid cluttering your thread with profanity but the whole "emissions test" thing here in Colorado is such a useless scam it isn't even funny.

In a nutshell, my truck was failed by some retard with a GED and a single digit IQ because my gas cap was "no good". Huh, so I didn't have any evap system codes (every vehicle sold in the United States since 1996 is required to monitor the fuel system integrity and will throw a code if my gas cap seal wasn't good) yet somehow this genius and his high tech vacuum pump machine say it's no bueno and fail me because I need a new cap.

Long story short, I have better things to do with my time so I replaced the damn cap and went back and they tested the new cap and passed me.

Two days later I now have a "gas cap loose" light on because the piece of shit aftermarket cap is junk. Being a little pissed off that day, I wasn't thinking clearly and tossed the original cap.

Looking forward to next time when they'll probably pass me even with the warning indicator that tells me my gas cap leaks being on because they'll likely test the cap and say it's good.

At least my vehicle is new enough that that they don't actually test my emissions when they do my emissions test. (Makes sense. They'll trust the on board diagnostics to monitor everything but won't trust it to monitor the freaking gas cap.) I hated having to watch some high school dropout with almost a year and a half of driving experience trying to run a vehicle on a dyno.

[TFOGGER]

My big bitch is that the geniuses they have run the cars on the dyno can't drive. My wife's 1995 Rodeo has always passed with flying colors. This last time, some millennial yokel that couldn't drive a manual managed to get it to fail because they couldn't keep up with the bouncing arrow on the display, and kept having to stomp on the accelerator. Fortunately, their extremely low level of competence extended to their typing as well, as they managed to get the license plate in the computer wrong. When I noticed the error (vanity plate, so it was glaringly obvious), I specifically requested that the vehicle be tested by someone that could drive a stick shift. Miraculously, the vehicle that had just failed miserably (high CO) now passed with emissions well within the limits. As a bonus, this drama took an hour and a half to play out, so I missed about an hour of work. I had a similar issue with my MR2 a few years back at a different station. Different driver, dramatically different result.

[TRnCO]

She said the law only applies to (now don't quote me here, because when I heard this I was SHOCKED) she said the law only applies to "something like" vehicles 2006 or 2008 or NEWER.

Is it possible that the people that work at the auto parts store and vehicle repair shops aren't aware of this, just as you weren't? Maybe a possibility. Hence the reason they didn't tell you this to save you the aggravation.

[10x]

Glad I live in the Springs and don't have to deal with that. Glad it worked out ok.

[Martinjmpr]

I'm pretty sure if you go to the Air Care web site it will tell you that they will only fail you for a CEL if your vehicle is under 13 model years old. 13 years or older and it is what's called an 'advisory fail', i.e. you can pass (assuming all the other parts work) but they are "advising" you to have the CEL looked at.

Also, FYI you can buy a dongle from Amazon that links to your phone and plugs into the OBD port that will let you reset the CEL. Cost is about $15 and you just need a free or low-cost app for your smart phone to reset the CEL.

Funny thing about emissions testing: On many modern vehicles they don't "test" anything. When I took my Suburban in they just hooked up the OBD reader, confirmed that everything was working and then I was done, passed. No dyno, no tailpipe emissions, nothing. Basically they just verified that the computer thought everything was working so they assumed it was.

[Big E3]

E-tests are a pet peeve of mine. Why if we can drive through a road side test, like at every on-ramp in Highlands Ranch, do we need a test station? They should just set up a quarter mile stretch of road let everybody needing a test just drive through and be done. Then just close all those buildings with all social reject clowns inside, that can’t drive a stick shift to safe their life.

[Eric P]

Or, keep the building. Use the road side tests and flag failing vehicles. Only failing vehicles need to go get tested.

But that would be unfair to the poor, so I'm told.

[Eric P]

I do have to keep a set of 33 inch tires for the test which is annoying. But funny when on the dino. Mud terrains make far more noise than any exhaust. They also don't know the difference between 4wd and awe. Even if they put mine in 4wd, it's still 2wd unless you lock the hubs.

One time I took it there and the xterra was swarmed by every tech. All looking at the engine a front wheel wells. I thought something was wrong, so i went out and they said since they could see all the cats and sensors, they wanred to show the newer hires what they looked like.

But these tests are a joke anyway. 99.x% of vehicles pass. But the silly EPA won't let Denver metro stop since we exceed level too many time per year. But they won't tell you a lot blows in from the west and no amount of emissions control on the front range will help.