emission test results

[Ebby]

We just had our car tested for the drive clean program and the HC ppm limit was 60 and the car got 60. We've checked the fuel pressure regulator and it's okay, the plugs only have 30,000 miles on them, so we don't know why we got a high reading. The limit for the NO ppm is 443 and the car got 38. If you would share your results for a 97 STS, our's has 90,000 miles, it would be appreciated. :

[JimD]

High HC levels indicate unburned fuel. If you are certain the fuel pressure regulator is 100% OK, you could have a drippy injector or two. A fuel pressure gauge can give you a clue with a leak-down test.

Fuel is the problem here and you want to be sure there is no way for un-metered fuel to get to the intake stream or combustion chamber.

Was this a tailpipe sniffer test?

[KevinW]

We just had our car tested for the drive clean program and the HC ppm limit was 60 and the car got 60. We've checked the fuel pressure regulator and it's okay, the plugs only have 30,000 miles on them, so we don't know why we got a high reading. The limit for the NO ppm is 443 and the car got 38. If you would share your results for a 97 STS, our's has 90,000 miles, it would be appreciated. :

I've attached DriveClean results from a 75,000 mile 1996 Concours (same powertrain as yours). What were your carbon monoxide readings? How is the car driven normally? How long was the car sitting prior to the test? I've seen HC readings drop significantly after giving it a good WOT blowout on the highway, and heading straight to one of the 'no appointment' test centres.

[Ebby]

OUr CO readings were 0.12 at 1513 rpm and .41 at idle. We had just gotten back from a 1800 mile drive to Virginia, from Ontario, and it was a twenty minute drive to the testing area, so the car got a good highway run prior to testing. It ran well for the long trip and got roughly 30mpg. How do you test for leaky injectors? the HC two years ago was 52, so it has gotten worse. One mechanic told us that the O2 sensors were shot but we have no codes up. Any help to enlighten would be appreciated.

[KevinW]

Those carbon monoxide readings are close to the expected ratio. You could test for leaky injectors by raising the whole fuel rail assembly and inspecting while the system is under pressure. An injector balance test may help to pinpoint uneven flow rates. I would say if there's no starting difficulty or visible smoke, and the car is running well, I wouldn't worry about the injectors.

What is the oil consumption rate?

1800 miles of "30 mpg" style driving (per Imperial gallon I assume) would not generate the necessary pressures/temperatures to clean-up everything. Periodic wide open throttle (WOT) blasts are essential to optimal engine and emission performance. I've seen HC numbers fall below a third of the original values after some WOT treatment.

[jgr7]

Change your oil before you go to the test place too, this helps as clean oil has less of the contaminates in the ring blow by that you get. The WOT to make sure every thing is cleaned up and the 2nd gear accel and decel to to make sure the rings are nice and free before you go is also a good idea. I would make sure that you start this at least a week before you go get tested. The other thing that can affect the HC is your cat converter not being in top shape, if you are burning alot of oil it could be degrading the Cat and causing it not to do the best job.

Jeff

[unc25]

I had a similar problem with my carb. accord, it turned out my timing was way to advanced. I dont know if this is even a possibility, but my high NO ppm was b/c of an advance in my timing.

[KevinW]

Here are some results from a 100,000 mile 1991 STS. No special preparation was made, and they left it idling for 10 minutes or so prior to the test. The aftermarket catalytic converter was installed roughly 30,000 miles ago.

[KevinW]

Here's another data point: 1989 Buick Century, 3300 V6, 137000 miles, original catalyst, 1500 miles on oil change, lots of high speed WOT driving just prior to test, no line-up at the test centre, a couple slightly leaky injectors (starts too quickly sometimes , consumes roughly a quart of oil every 6000 miles.

[jgr7]

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[Scotty]

Here is the smog test from my 94 Eldorado 135k+ miles. This is run on a tredmill here in Calif.

Jeff

That is a pretty impressive test that they did, leave it up to california. New York is not as sophistocated. Did I read it right that you have to do it twice a year? Mike

[jgr7]

Sorry I tried to edit twice and the board wouldn't let me so I redid it again.

kind of a mess but you can see the info.

Scotty no its every other year.

Here is the smog test from my 94 Eldorado 135k+ miles. This is run on a tredmill here in Calif.

Jeff

Smog Check Vehicle Inspection Report (VIR)

Vehicle Information

Test Date/Time: 04/16/2004 @ 10:58

Model Year: 1994 Make: CADILLAC

License: n State: CA

Engine Size: 4 . 6 L Type: Passenger

GVWR: N/A Test Weight: N/A

Odometer: 135818 Certification: California

Fuel Type: Gasoline Exhaust: Single

Model:

VIN: Transmission: Cylinders:

VL T Record #: Inspection Reason:

ELDORADO

1G6EL12Y Automatic

8

13523

Biennial

Overall Test Results

Congratulations! Your vehicle passed the enhanced Smog Check inspection. which helps California reach its daily goal of removing an extra 100 tons of smog-forming emissions from the air. Thank you for keeping your vehicle well maintained.

Smog Check Certificate Number: FJ858122 DMV 10 Number: 4616JO81F554

Your Smog Check certificate has been electronically transmitted to DMV. Your certificate is valid for 90 days from date of issuance.

Please keep this copy for your records.

Result Pass Pass

Pass Pass Pass Pass Pass N/A

Emission Control Systems Visual Inspection/Functional Check Results (Visual/Functional tests are used to assist in the identification of oxides of nitrogen, crankcase and cold start emissions which are not measured during the Idle test)

Result N/A N/A Pass

ECS

Thermostatic Air Cleaner Air Injection

Vacuum Lines to Sensorsl

Switches

Ignition Timing:

Wiring to Sensors

Fillpipe Restrictor

Result Pass Pass Pass Pass

ECS

Fuel Evaporative Controls MIL/Check Engine LigLt Carb./Fuel Injection Other Emission Related

Components

OxYgen Sensor

liqUId Fuel Leaks

ECS

PCV

Catalytic Converter

EGR Visual

EGR Functional

Fuel Cap Functional N/A

Fuel Cap Visual Pass

Spark Controls N/A

Fuel Evaporative Controls Functional

Pass Pass

Idle Emission Test Results

%C02 %02 HC (PPM) CO(%)

Test RPM MEAS MEAS MAX AVE MEAS MAX AVE MEAS Results

Idle 655 14.6 0.3 100 17 38 1. 00 0.00 0.03 PASS

2500 RPM 2538 14.5 0.5 130 12 8 1. 00 0.10 0.00 PASS

-

MAX = Maximum Allowable Emissions

AVE = Average Emissions For Passing Vehicles

MEAS ;'Amount Measured

Scotty no its every other year.

[Scotty]

New York is annually but they don't really do the physical inspection that Calif has unless its visual and implied. I forget what its called but the car is on a roller sort of like a dyno probably similar to yours and they drive the car via speed over a simulated track on a computer screen. I think its pretty cool watching the car doing 55 standing still. I have to make sure I get the tape next time, they neglected to give it too me last time..