Ok, I removed the MAF and used MAF cleaner to clean it thoroughly. Once dried, I put it back on. Started and the lights still on. Next step is the premium gas once the current tank is about empty.
You neglected to say if you reset the light after cleaning the MAF. Reset the code and then see if it comes back.
Which engine do you have, the 3.0 pushrod or the 4 cammer?
The light will NOT go out by itself. You need to cancel the code with the reader. That will put the light out. Then you need to complete a drive cycle. Google it - there is a procedure you can go through that will reset all of the monitors except the evap monitor in about 20 minutes of driving, or it may take several days of random driving to reset the monitors. The catalyst monitor needs to reset before the light can come back on - and the monitors all (or all but 1 - or possibly 2) need to be set before it will pass inspection.
If you have the 4V duratec engine, as i recall, this engine had issues with a PVC or vacuum hose under the intake plenum that can cause air leaks when i cracks from aging.
bob
Was common on the 2.5 in the Contour/Mystique in 1996-97. I thought they had fixed it on the '99 and up 3.0 in the Taurus but it is definitely worth a check. I did have that problem on our old '96 Mystique - chased that lean condition for weeks. It only went lean on decel - high vacuum collapsed the hose, opening the crack. Roughly half inch hose coming off the bottom of the throttle body on the mystique - and in 2002 it was already discontinued from Ford and was a "dealer only" part. I found a moulded heater hose at Napa that fit by cutting a bit off.
That's why I asked what engine, becuase the Essex and the Duratech are too totally different animals and we don't want to be giving solutions for the wrong engine.
Cancelled the code; tomorrow I will try out the drive cycle. Very interesting stuff, I must say. Never knew about "drive cycles".... always thought just fish and plants had cycles (chuckle).
So I guess I can assume now that, once the drive cycle is completed, the lights will stay off and the car should pass inspection? Not so sure from what you say above.
Sam
Reset it tonight, but will complete the "drive cycle" tomorrow.
Forgive the maybe elementary question, but what's the best way to find out which engine I have?
Eight digit of vin code
Google and look at the pictures. The Essex/Vulcan pushrod engine has narrow valve covers and is lost under that big hood. The Duratec has WIDE covers and fills the hood. The plugs on the essex/Vulcan come out the side of the heads and are visible. You almost need to be houdini to find the plugs on a duratec. On some cars with the duratec there is a "32 valve" emblem on the fender.
Or just check the 8th digit of the VIN code.
3: 3.0 (OHV) Essex U: 3.0 (OHV) Vulcan S: 3.0 (DOHC)
Ok, 8th digit is a U, so 3.0 OHV Vulcan
Alright, yesterday I cleared the codes, let the car sit overnight, and did the drive cycle this morning as described here:
Since DTCs cleared MIL() OFF MIS() OK FUEL() OK CCM() OK CAT() INC HCAT() N/A EVAP() INC AIR() N/A O2S() OK HTR() OK EGR() OK
IIRC, it seems that not everything was tested... CAT and EVAP ring a bell and the yellow caution light was illuminated on the scanner.
Not sure what this means. So far, no return of the check engine light on the dash.
I did not do any data checks yet like I did yesterday, just the I/M readiness test.
All monitors are complete and ready, except the Evap and the CAT. It is common that these are the last to complete.
Just because you drove a qualified drive cycle does not mean that the monitors will clear/complete. If they detect any abnormality in the data they monitor then they can take an additional drive cycle, or two or three or more.
EVAP is the system that collects gasoline fumes and returns them to the fuel tank to begin the journey anew. Evaporative emissions are emissions that occur before combustion, basically raw fuel escapes to the atmosphere. These emissions are captured and returned to the fuel supply -- there are various ways to accomplish this, different car makers will use different methods -- and you are waiting for the system to be sure all compoinents within it have strong integrity. This system is not directly related to the codes you asked about, that is this system will not cause a LEAN condition.
CAT is the exhaust emissions, or catalytic converter. The exhaust emissions look at the exhaust going into the CAT and the exhaust coming out. The exhaust going in is analyzed for air/fuel ratio and the computer uses the results along with the input from the MAF to set the fuel injector timing. The data from these sensors is a direct feed to the codes you have, although not necessarily the cause of the codes that you have. You can have a false LEAN, in which case the sensors are failing. Or you can have a true LEAN, in which case you have something to fix. There are sensors before and after the CAT, your issue comes from information collected by the sensors before the CAT.
That simplifies things then - at least on that engine it is POSSIBLE to see and reach just about everything of importance. The S code Duratec is packed in pretty tight!!!
The evap won't set if the tank is too full or too empty, or the temperature is not within range.. The cat might not set untill the second or third cold start cycle. Light being off is a "good thing"
Inless there is a leak in the system on the manifold side of the sensors - but USUALLY that will also set an evap code.
A failing O2 sensor on a Ford will almost invariably give a cat failure or O2Sensor failure code, not a lean engine code - and the chance of both banks failing at the same time is EXTREMELY slim. The problem is most likely caused by something common to both banks. That is MAS sensor, Fuel quality, or main plenum air leak (including anything the taps into the main plenum or throttle body)
Ok, I decided to reconnect the scanner and had it record data at both idle (~700 RPM) and 2500+ RPM. Here is what it recorded:
Live Data Number of DTCs stored in this ECU 0 Fuel system 1 statusCL Fuel System 2 status-- Calculated LOAD Value(%)27.1 Engine Coolant Temperature(¡£C)87 Short Term Fuel Trim -Bank 1(%)15.6 Long Term Fuel Trim - Bank 1(%)25.0 Short Term Fuel Trim -Bank 2(%)12.5 Long Term Fuel Trim - Bank 2(%)25.0 Fuel Rail Pressure(gauge)(kPa)270 Engine RPM(rpm) 698 Vehicle Speed Sensor(km/h)0 Ignition Timing Advanece for #1 Cylinder(¡£)26.5 Intake Air Temperature(¡£C)6 Air Flow Rate from Mass Air Flow(g/s)2.74 Absolute Throttle Position(%)18.8 Location of Oxygen SensorsB1S12--B2S12-- Oxygen Sensor Output Voltage Bank 1-Sensor 1(V)0.660 Short Term Fuel Trim Bank 1-Sensor 1(%)13.3 Oxygen Sensor Output Voltage Bank 1-Sensor 2(V)0.840 Short Term Fuel Trim Bank 1-Sensor 2(%)N/A Oxygen Sensor Output Voltage Bank 2-Sensor 1(V)0.065 Short Term Fuel Trim Bank 2-Sensor 1(%)16.4 Oxygen Sensor Output Voltage Bank 2-Sensor 2(V)0.835 Short Term Fuel Trim Bank 2-Sensor 2(%)99.2 OBD requirements to which vehicle is designedOBDII
Number of DTCs stored in this ECU 0 Fuel system 1 statusCL Fuel System 2 status-- Calculated LOAD Value(%)22.7 Engine Coolant Temperature(¡£C)85 Short Term Fuel Trim -Bank 1(%)5.5 Long Term Fuel Trim - Bank 1(%)5.5 Short Term Fuel Trim -Bank 2(%)5.5 Long Term Fuel Trim - Bank 2(%)7.8 Fuel Rail Pressure(gauge)(kPa)270 Engine RPM(rpm) 2753 Vehicle Speed Sensor(km/h)0 Ignition Timing Advanece for #1 Cylinder(¡£)47.5 Intake Air Temperature(¡£C)6 Air Flow Rate from Mass Air Flow(g/s)13.78 Absolute Throttle Position(%)27.1 Location of Oxygen SensorsB1S12--B2S12-- Oxygen Sensor Output Voltage Bank 1-Sensor 1(V)0.720 Short Term Fuel Trim Bank 1-Sensor 1(%)0.8 Oxygen Sensor Output Voltage Bank 1-Sensor 2(V)0.775 Short Term Fuel Trim Bank 1-Sensor 2(%)N/A Oxygen Sensor Output Voltage Bank 2-Sensor 1(V)0.565 Short Term Fuel Trim Bank 2-Sensor 1(%)0.0 Oxygen Sensor Output Voltage Bank 2-Sensor 2(V)0.750 Short Term Fuel Trim Bank 2-Sensor 2(%)99.2 OBD requirements to which vehicle is designedOBDII
From what I see, the fuel trims sharply drop which, according to some information I've come across, indicates a vacuum leak. Since the fuel pressure values seem to appear the same (270 kPa), I don't think the fuel filter or pump are concerns here. What is the consensus? I think it may be time for a smoke test since I have been unable to find anything with propane or carb spray tests.
Something interesting also occurred. When I re-ran the readiness check, it of course came up with the CAT and EVAP not yet ready, but a pending code is PO300. This is the first time anything like that has been pending, only the 171/74 were designated before when I cleared them.
I think the lights will be coming back on once the tests are complete, unfortunately.
P0300 is a multiple cylinder random misfire. It can be the result of the lean condition. So, we are back to Day 1, you have a vacuum leak somewhere. Air that has not passed through the MAF is getting into the engine (intake) somewhere.
Random Misfire.
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