ASM EMISSIONS TEST RESULTS - CODE P1406

I means that the vehicle failed it's emissions test as it failed the digital trouble code reading test 3
the testing station tests the exhaust emissions and the onboard computer
Your computer failed the test

P420 is EGR system malfunction P1406 is EGR pintle position problem be sure and check power and ground before condemning the valve and the P401 is catalyst code i would fix EGR code first clear monitors and run a drive cycle to see if the cat code returned although the egr and catalyst are separate systems an EGR that isn't functioning may cause the emissions levels to be too high for a marginal converter to diffuse resulting in the cat efficiency code

have the obd codes checked, once they get checked, post the results here, and we will be able to better help you in a solution, I can assist you in defining what the codes mean, and how to repair your vehicle so that your emissions will drop below the required amounts so that you will pass the test

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.

any check engine lights on sounds like a oxygen sensor

DTC P1406 IS EGR VALVE PINTLE POSITION CIRCUIT MALFUNCTION CONDITIONS.POSSIBLE CAUSE EGR SOLENOID CONTROL CIRCUIT IS OPEN SHORTED TO GROUND OR TO B+ -CHECK EGR VALVE FUSE - OR THE EGR VALVE AND PCM HAS FAILED.

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

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.

Hi........
On your LS.
The CODE P1406,
IS Mean: Differential Pressure Feedback egr. problem.

Ok.. Is just the definition for your code.
The DPFEGR.. is a Little BOX. Black Colour.

Is Normally connected to the EGR tube coming from the EXUAST MANIFOLD. with 2 small hoses.
Inspect the Hoses for broken, burn or stuck with carbon.
if you DON'T found nothing wrong.
Replace the DPFEGR. You van get from DEALER.
DON'T get from autoparts because they only offer one
UNIVERSAL. and most cases don't work right.

Ok.. I hope this help to try to fix your car.
Thank you for use fixya..