I'm aware of two related issues here
- Does Check Engine Light Clear Itself...
- I need the correct 2010 ... drive cycle steps to clear a “Permanent ” P0456 code
I've just completed a particularly nasty repair on a Mazda3, where the top of the fuel delivery module lock ring had a crack in it, and was leaking. I'm trying to get clean before going to the state to get a retest.
- I know if you clear codes, then drive to the local emission testing station that will get you an immediate rejection.
Edit here... not sure why folks are having trouble understanding this one... Its called a "not ready" failure.
New York has adopted the federal Environmental Protection Agency (EPA) guidance concerning readiness during OBD II inspections. A vehicle will fail the (NYVIP2) OBD II inspection if enough monitors are reported as Not Ready.
Any of the following may cause your vehicle to not be ready:
Disconnecting the battery for any reason. This erases the memory in the PCM, including stored fault codes and previous OBD monitor test results. It's like resetting the clock back to zero. Consequently, it may take several days (or even weeks) of driving before all of the monitors will run, allowing your vehicle to be tested.
Erasing stored codes with a scan tool. This also resets all of the monitors back to zero, so allow plenty of time for the monitors to run before driving back to the emissions test facility. If any of the erased fault codes reappear, it may prevent one or more of the monitors from completing.
My state has exactly the same criteria as New York. end of edit...
- Based on that, I was thinking that my best course of action was to not clear any stored codes, and do drive cycle testing up until the point the check engine light went out on its own. This is the generally the recommendation in "Does the check engine light clear itself..." posting.
Here's my only issue... While doing web searches to understand the drive cycle required to clear codes, I ran across the State of New York Vehicle Inspection Program website. That site is extremely detailed, and of high quality content.
Something there really caught my eye. On the page for "Helping Set Monitors" I see
An example of some common enabling criteria to run the EVAP monitors drive cycle:
- The malfunction indicator lamp (MIL) must be off <--- HUH??!?
- Barometric pressure exceeds 75 Kpa
- At start-up, IAT and ECT is between 45°F and 85°F
- IAT is not more than 2°F greater than ECT
- ECT is not more than 12°F greater than IAT
- Fuel tank level is between 26 percent and 74 percent
- The TPS is between 9 percent and 35 percent
- The EVAP solenoid is at 50 percent pulse width PWM, within 65 seconds of engine run time
Abbreviations: IAT - Intake Air Temperature, ECT - Engine Coolant Temperature, TPS - Throttle Position Sensor, PWM - Pulse Width Modulation
Whoa.... look at that first item,
the malfunction indicator lamp (MIL) must be off As I read that, and if its true, that would mean, no matter how much drive cycle testing I do, no way will I every be able to clear the MIL lamp. This seems to directly contradict
Does Check Engine Light Clear Itself... posting. I've been out on the highway performing testing, and everything in the current drive cycle shows passed, EXCEPT
Evaporative System, sigh.
Anybody been here before? Any hints and tips on how to get thru a US state emission test, after a successful repair? Yes, its possible that I missed something on my fuel delivery module lock ring repair, but I don't think so.
Do I stay the course, keep doing the recommended test drives until the lamp goes out, or do I clear the codes, then do test drives?
If I do instead decide to clear the codes, how much testing on a clean slate is required to get a go at the inspection station?
Anybody been here before? thanks...