California Smog Test rip-off??? - PeachParts Mercedes-Benz Forum

BENZ-LGB · #1 12-03-2002, 01:21 AM

I would like to know your opinion regarding the following situation.

I own a 1991 420SEL with 224K miles. The car runs great, smooth idle, easy starts, all in all a joy to drive.

The car was due for a smog test for this year's registration renewal. I took it to a local smog-only test site. (In California older cars must be smogged at a smog-only test. The theory being that older cars are more likely to fail the test and so the state wants to avoid the temptation of service stations trying to get older cars to pass the test by selling unnecessary service work).

Anyhow, the tech came back and told me that my car had failed the test. The readings were way off for NO and for CO2. My car runs well, so I was surprised to hear that my car had failed. The tech appeared to be sympathetic, he asked if I had a "real good mechanic" to work in my car. He then he handed me a list of local mechanics who could work on my car and test it before I would bring it back to him for a re-test. He also added that I probably needed a catalytic converter.

Somehow I had a bad feeling about this smog guy. So I went to another smog-only site. They tested the car and bingo, it passed.
Not only did the car pass, but the NO and CO2 readings were significantly lower than the first test.

I had done nothing to change the car's smog performance. When I looked at the two test results the only difference (other than the lower readings for the second test) were that for the passing test the tech had higher RPM readings at 15 mph and 25 mph respectively than the failing test. For the failed test the RPM were 1385 and 1414 for the 15 mph and 25 mph test respectively. In the passing test the tech had the RPM at 2134 and 2050.

Is the difference in RPM readings enough to produce such dramatically lower results for the second test? Do higher RPM readings produce lower NO and CO2 readings? Was the first tech trying to steer me toward an expensive repair (cat converter)? Was the first tech just plaini ncompetent? And more importantly, shouldn't these test be uniformly given and administered so that all cars that deserve to pass the test pass and the bad polluters fail?

What do you all think???

anthonyb · #2 12-03-2002, 02:33 AM

I don't know what the specific test requirements are, but the rpm readings for my 1987 300E were about 1700 rpm for both 15 and 25 mph. You may want to call a couple of test-only places (maybe even the shops you went to) and ask them how this works - how their machines are calibrated, etc.

If you think the first shop was pulling a fast one, you should contact the Bureau of Automotive Repair (http://www.smogcheck.ca.gov)to file a complaint. They get a lot of complaints about the whole smog check deal (surprise, surprise) - I bet they don't appreciate getting extra ones because some shops are being sleazy.

-anthony

hill · #3 12-03-2002, 03:07 AM

Kind of a funny smog story. Before the older cars were exempted in California I took in my 68 Land cruiser for smog. It was running sweet but it failed. I looked at the HC NO CO standards that it had to pass and they were real low. So off to the state BAR smog shop we go. In the parking lot waiting for testing was a 68 vette, 68 GTO, 68 Charger etc. Apparently due to some snafu we had all failed 1986 smog standards.

Glen · #4 12-03-2002, 10:19 AM

My first thought would be that the car wasn't completely warmed up. High C02 would indicate low O2 meaning a rich condition. It's possible that by the time you arrived at the second smog station the car and cat were fully heated and working correctly.

BENZ-LGB · #5 12-03-2002, 10:51 AM

The emissions test that my car failed at the first shop were the NO and the HC, the CO levels were fine in both tests.

The second shop is less than five minutes away (maybe 10 with real bad traffic) from the first shop.

What concerned me about the first shop was: (a) the guy's attitude (he said to me, "the State wants to get rid of these old polluters..." "Old polluter"??? My sweet Benz? Hell no!) and (b) he was way too ready to hand me a list of nearby shops that could fix my "problem."

I sent the shop a letter demanding a full refund of the test fee. If they do not respond I will take them to Small Claims court (I hate doing this for $50.00, but it is the principle of the matter that counts). I will probably also report them to the Bureau of Automotive Repairs (BAR). I have the feeling that there is something sleazy going on here.

I'll keep you guys posted.

Jim Anderson · #6 12-03-2002, 12:04 PM

You could go back to the first place and re-test and see what the numbers are.

Hottexhaust · #7 12-05-2002, 01:42 AM

High Co usually indicates a rich condition....High NOx is a lean condition.......to fail on both could mean an inoperative CC..OR failure to bring the car to normal operating temperatures...necessary for the CC to light off

luvrpgrl · #8 01-29-2005, 02:30 AM

I would just be happy and keep going to the second guy

)

Ha, actually, I would do as another suggested, report them.

boneheaddoctor · #9 01-29-2005, 12:45 PM

Hi NO2 readings are indicative of excessive combustion tempratures....IE lean condition.........

Overly rich conditions would fail on excessive hydrocarbon emmisions.

Hatterasguy · #10 01-29-2005, 12:51 PM

You could try some of that Guarantee to Pass stuff the auto parts stores sell. Or rubbing alcohol will make any old beater pass.

Disclaimer use alcohol at your own risk!!!!! I have no idea how the parts for a fuel injected engine will react. But it works well with carbs.

Or you could try to fix it, I would try to fix ir if I was going to keep it.

dieseldiehard · #11 02-23-2005, 07:43 PM

There is more than meets the eye with this smog test stuff. I don't own a car that needs smog checks but I have a friend that does. He recently went through similar circumstances as BENZ-LGB.
First, note that he always has a service performed prior to testing, including an oil change, new plugs, O2 sensor and fresh tank of hi octane, etc. He recently took his car to a smog only garage and the man commented that it really met the levels easily and will passe "no problem" Car is a Volvo 240 with Bosch FI engine and a stick shift. Keep in mind he needed to go to the test only site next, it was just a mile away, to get a certificate for the state of Crapifornia. And yes he made sure his catalytic converter was good and hot.

When tested, the car failed! He asked them to retest it they did and it still failed, he insisted something was wrong, he happened to have a friend along that knew the owner of the place and they together said it had just passed a smog only test. So the owner of the shop moved a large fan over to the front of the car, switched it on high and ran the test the third time and it passed with flying colors. The theory I have is that the Mass airflow sensor or something in the front of the engine needs cooling air or air flow to read the proper signals into the computer. I do not know which parameter failed, all I now is it failed some spec big time.
The car is sitting there with its engine loaded by the dynomometer type load (they will tell you its not a dyno at all, just loaded cylinders that the wheels are driving) with no air flow, very unlike the real world where air is blowing into the front of the car.

So you see, this whole system is a bunch of non scientific hogwash. The shop owner even sugested he call the BAR while at the same time he said they know that since they started using these dyno things they have had tons of problems like this.

Lastly, be warned anyone that owns a stick shift car, most of these Smog test places do NOT know how to shift stick transmissions! 90% of the cars they see are automatics. My friend said one guy ground his gears real bad. And they are supposed to put it in 3rd gear I believe but he revved the ***** out of it in 2nd and didn't use the clutch one time he tried to shift gears. Your insurance company won't cover it if they waste your synchros or worse!
Smog Checks Suck! Just ask Texas. There they scrapped the whole plan after the courts decided this was wrong from the start. This after many people invested a lot of their own money in building smog test centers to a State supplied specifications. Lawsuits are probably still running in the courts there.

All this is yet another reason I DRIVE DIESELS!

Ashman · #12 02-23-2005, 08:18 PM

when I had my car smogged, the first time it failed the test. The guy at the test station told me, let me run it again, sometimes after the car has been sitting for a while and then they start the test it will fail. (my car had been sitting for 30 minutes before they got around to test it.) So I guess not everything was fully warmed up.

After he ran it again, it passed with flying colors well below the maximum allowed readings.

I always go to this test station with my cars, ACC on Robertson Blvd near national. They are a test only station, and have yet had a car not pass. the guys there know how to do the test, and if it fails they won't try to send me to some mechanic for repairs.

If my car did fail, I'd just drop it off at my mechanic, and have him get it smogged for me so he could adjust it if need be.

My car too runs great.

Alon

olpos · #13 02-23-2005, 11:10 PM

The person who did the test wrong was the place that passed you. If you complain about the first guy that tested you , the guy that passed you will be the one who gets in trouble with bar.Your car should be tested in drive 3, not in overdrive.those are the rpm readings from your first test. correct
The second person tested it with the shifter all the way down (low)
that gave you high rpm and differant readings
The first person could have passed you if he did it again or did a tire dry run before the test. I always do mercedes twice. very differant readings the second time. These cars have great cats but take a lot to get them to turn-on
Thanks
Rich

Ashman · #14 02-24-2005, 01:16 AM

yeah the guy at the smog station I went to told me the cars need to be really warmed up. thats why he ran it again.

I always watch them, and they did the test the same way they did the first one.

Alon

dkveuro · #15 02-24-2005, 01:45 AM

'Corse....Yous could all just sell up an' move to Okleeeehoma....
We don't need no stinkin' Smog Test !