Question about 1996 Chevrolet Suburban

Open Question

'96 Chevy Suburban K1500 ASM Emission Test Results were high in CO(%) at 15mph, engine not running long and luke warm, everything else passed and no problems at 25mph. What could be problem/replaced to get SMOG test passed?

Posted by on

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

I rebuilt the TBI, Changed every sensor in the truck and replaced the heads. I still cannot pass the CA smog test


Check everything that is connected to a vacuum line, check the CAT and the injectors and last run a compression test.

Mar 13, 2014 | 1988 Chevrolet K2500

1 Answer

How to fix asm emission test failure hc( ppm) max 61 gp 274 meas 690 at 15 mph, at 25 mph max 36 gp 224 meas 804


this is easy,, it can be 1 or 2 problems.

1: CAT is dead or weak, new cats can in fact hide a crappy engine.

2: bad engine. runs like junk and does not burn all its fuel.



any good shop can find this is minutes.

what I DO (no 5gas mach)

i check for (scan tool costing me $9 whole bucks) ask)

i check for closed loop status, idling

if ok then at 15mph and then 25mph , just racing motor in neutral.

if all 3 tests pass, im good.

if any fail, i fix that. bad fueling, bad spark or whatever.



if all 3 pass, its NEW CAT TIME



easy huh? a binary answer.

bad cat, bad motor. (or both)



when i say bad motor that means,every inch of the EFI/engine system.

every drop.

Dec 27, 2013 | 1994 Honda Civic

1 Answer

ASM EMISSION TEST RESULTS AT 15MPH FAILED. WHAT SHOULD BE REPAIRED?


You have to look at the exhaust gas readings

Sometimes in my State on newer cars, they don't give you that
I have to go to the MV Web site to see the report in full

A high CO would be a rich condition
A high NOX would be overheating

Then the other gases etc

Now if you want a complete manual or set of instructions
for every diagnostic procedure to correct something,
your asking far too much.

So let me know if you work on your own vehicles
If not go to a repair shop

Sep 22, 2011 | 1996 Ford Ranger SuperCab

2 Answers

My 1997 Honda Civic failed it's Emissions Test. See below the ASM Emission Test Results. What do you suggest I do to get the car to pass the smog test? ASM Emission Test Results: 15mph - RPM = 1587...


Jose, I don't know if this will give you the answer you are looking for because there are many things to consider here. The exhaust gas recirculation valve (EGR) is one of the main things involved in reducing NO emissions. This valve is controled by the power control module. (PCM) This is your vehicles computer. The PCM monitors the vehicles speed and will command the EGR to open when the vehicle attains a certain speed, which is why the ASM test being done is recorded at two different speeds. At 25 MPH your vehicle failed the hydrocarbon (HC) emissions limit and this could be for a number of reasons. When is the last time you car was tuned up? Old spark plugs, wires, clogged air filters, oxygen sensors, leaking injectors (personal experience) or the PCV valve could be contributing to the results of the test. I guess that the easiest way to go is to tune up the engine replacing the spark plugs, wires, air filter and the PCV valve and don't forget to have the oil changed at the same time. Only then should have the vehicle retested and see what the results are. Should it fail again you may have to consider having the EGR or the catalytic converter replaced depending on what portion of the test fails. If the NO fails I would consider the EGR. If the HC fails then I would consider the catalytic converter. Good luck with this.

Apr 05, 2011 | 1997 Honda Civic

1 Answer

My 1990 chevy astro van didn't pass smog. Paperwork says it failed the following; Ignition timing: 99 ATDC. Also, ASM Emission Test Results; 15mph HC (PPM) max is 122 measured 127, 25mph max is 102...


the smog test looks like the engine is miss firing, that could cause the timing to be out of whack also, try a old fashioned tune up, new spark plugs, wires, and filters also replace the PCV valve. any time you see the NO that high suspect a miss fire.

Feb 24, 2011 | Chevrolet Astro Cars & Trucks

1 Answer

Failed smog check


How well does the vehicle run?

Assuming that the engine did pass the EGR function test on the emission test results, and the MIL (Malfunction Indicator Light) or check engine light is not on when the engine is running, and if you are not sure when the last time it was that the engine had a complete tune-up, with distributor cap, ignition rotor, spark plugs, spark plug wires, air and fuel filters, then a complete tune-up would certainly help, and if the engine oil and oil filter have not been changed in a while, then they should also be changed before an emission test because long used engine oil traps carbon and it will show up as higher CO on the emission test because the emission analyzer will be able detect the higher CO from the engine oil through the PCV valve.

However, it would seem from those HC readings that there is a vacuum leak, and carefully inspect all of the vacuum lines for any cracks or damage, (especially the vacuum line to the fuel pressure regulator) because cracks in the vacuum lines seem to like to hide underneath the lines.

The emission label under the hood should have the vacuum line routing diagram printed on it, and the vacuum lines should all be checked to be certain that they are all connected correctly.

Here is the firing order diagram for that vehicle to help assist you tune-up the vehicle.


e696e87.jpg

Jul 09, 2010 | 1997 Honda Civic

1 Answer

1991 Honda Accord LX failed EVAP test. The ASM Emission Test Results showed Test 25mph RPM 1933, %C02 MEAS 14.60, %02 MEAS 0.22, HC (PPM) MAX 61, GP 236, MEAS 19, CO (%) MAX 0.60, GP 2.10, MEAS 0.02, NO...


Things to consider or replace...

If you are getting a Check engine Light let me know, it will make things easier to diagnose.

Catalytic Converter
Oxygen Sensor
EGR Valve

May 17, 2010 | 1991 Honda Accord

2 Answers

Ford failed MOT on High CO emission


High CO usualy means the O2 sensors are not reading properly. Take it to a parts store that can read codes, I know Auto Zone does in my area. If it is the O2 sensor it is an easy fix but the sensors run about $50.00 each.

Apr 18, 2009 | 1995 Ford Escort

1 Answer

My car just failed smog emissions test, had high nox count, at 15 miles about double max allowed, at 25 mit iles per hour, triple max allowed. The car is a 91 plymouth voyager.During the test it smoked...


i would put a good tank of gas in the system. like 93 super.drive the car for about 1 week or at least 100 miles. i would also go to a good auto parts store.u should be able to buy a bottle of engine cleaner to pass the smog test.also when u bring the car in for the inspection.take it for a rideand get it nice and warmed up.

Mar 10, 2009 | 1991 Plymouth Voyager

Not finding what you are looking for?
1996 Chevrolet Suburban Logo

211 people viewed this question

Ask a Question

Usually answered in minutes!

Top Chevrolet Experts

yadayada
yadayada

Level 3 Expert

75005 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22095 Answers

Jeff Turcotte
Jeff Turcotte

Level 3 Expert

7710 Answers

Are you a Chevrolet Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...