System Too Rich

[97TaurusGuy]

I just bought a 2001 Taurus SE. I just pulled codes P0172 and P0175, system too rich bank 1 and 2. Not knowing anything about the cars history, where should I start to remedy this. I do know the car sat for 4 months and when I received it the fuel tank was just shy of being dry. Any ideas?? Thanks!!!

[shorod]

I used the very effective search tool from the Taurus forum main page and quickly came across the following which may be of use (see the TSB posting from Huney1 in post #12 in the first thread).

http://www.automotiveforums.com/vbul...ighlight=P0172
http://www.automotiveforums.com/vbul...ighlight=P0175

-Rod

[Huney1]

Do what Shorod said and read through my threads because there is an extended warranty on the PCM and yours might be eligible for free replacement. That is, IF the PCM is in fact bad and the Ford place pulls the codes verifying it needs replacing.

This will sound mighty strange, but here's what a guy at Advance Auto told me to do to cure the surging, and it worked. Drive it until it gets to normal operating temp then park it and disconnect the negative battery terminal, let it sit all night then connect the battery terminal and somehow that resets the computer. When you first crank it don't race the engine, let it sit and idle for 15 or 20 minutes then drive it for an hour or so at highway speeds and around town speeds. If it doesn't work the first time try it five or six nights and eventually it should straighten itself out and the surging and loping mine was doing went away. I kept getting the CEL light so I replaced the sensor before the cat next to the firewall, sensor 1 bank 1, I think it was, and the CEL light went off and hasn't come back on in over 5K miles, so I guess it's fixed.

OH! Get a can of electrical parts cleaner and clean the MAF wires. Very delicate wires and do not touch them, just spray them off and let them dry a few times and that is all. MAF = Mass Air Flow sensor. On my 03 it's in the air duct after the air filter. Here's how yours looks but mine is a flat little rectangle box 'bout big as a small box of stick matches. http://cgi.ebay.com/ebaymotors/01-04...QQcmdZViewItem

[way2old]

Also check fuel pressure. If regulator is bad, you can get those codes.

[97TaurusGuy]

Alright, I did what Huney suggested. I disconnected the battery, let it sit overnight, and reconnected it in the morning and let it run for about 15-20 minutes then drove it down the highway. All seems well, no more surging, no CEL. My only problem now is my computer wont go through all the cycles to be ready for inspection. The scanner I bought shows if it is ready or not and my Evaporative System Monitor. I even tried the procedure again and still not ready. I followed Ford's recommendations in the Owners manual on page 200 to reset the computer. Any ideas??

[TaurusKing]

That's what happens when you turn off the check engine light, it resets all the monitors to "not run".. in part so you can't turn off the cel and have it pass emissions testing if required, do a search for " obdII drive cycle" for your car, someone on here may know, it's in my books, I'll try to come up with it..

[97TaurusGuy]

I stated in my previous post that i already knew that. All other systems are a go. Just the Evaporative System Monitor is not "resetting". It has been about 200 or so miles since I cleared the codes out. I followed Ford's drive cycle to a T a few times over.

[shorod]

According to the factory service manual, "The Evaporative Monitor can only operate during the first 30 minutes of engine operation. When executing the procedure for this monitor, stay in part throttle mode and drive in a smooth fashion to minimize 'fuel slosh'." You may want to go through the tests again in the first 30 minutes if you have not already.

I'm not sure where you got your drive cycle information, but this is what is in the factory service manual:
"Cruise at 64 to 128 Km/h (45 to 65 MPH) for 10 minutes (avoid sharp turns and hills). NOTE: To initiate the monitor TP MODE should = PT, EVAPDC must be > 75%, and FLI must be between 15 and 85%."

The purpose of the drive cycle is it "Executes the EVAP monitor (If IAT is within 4.4 to 40°C (40 to 120°F)."

-Rod

[97TaurusGuy]

I got my drive cycle information right from my owner's manual. It says to drive for 10 minutes on the highway (around here that is 65mph) and then 20 minutes city driving with at least 4 idle periods.
>"The Evaporative Monitor can only operate during the first 30 minutes of engine operation"< Does this mean 30 minutes from intial engine operation after resetting the monitors or 30 minutes anytime the engine is started?? And would fuel level effect it at all?? And would outside tempeture effect anything as well??

[way2old]

The evap monitor will not run if fuel is below 1/4 tank or above 3/4 tank of fuel. These are approximates. I believe the figutes are 15% and 85%. The evap monitor will run on each system start up.

[97TaurusGuy]

ok, my tank has been around half or so. So what about the outside temp, will that effect it??

[way2old]

Outside temperature should not have any effect on running the monitor. The only thing it would affect could possibly be a seal that has contracted due to cold temoeratures. But if that were the case, there would be lots of vehicles with the same problem.

[97TaurusGuy]

I drove the car today just as shorod read off form the service manual. The evap Monitor is still not ready. I can't get the car inspected until it is all set. Any other ideas??

[shorod]

Does your MAF sensor seem to function properly? The following note is from the service manual regarding the description of the EVAP monitor:

"Note: During the EVAP Leak Check Monitor Repair Verification Drive Cycle a PCM reset will bypass the minimum soak time required to complete the monitor. The EVAP Leak Check Monitor will not run if the key is turned off after a PCM reset. The EVAP Leak Check Monitor will not run if a MAF sensor failure is indicated. The EVAP Leak Check Monitor will not initiate until the Heated Oxygen Sensor (HO2S) Monitor has completed."

Also, does your scan tool read the Ford manufacturer-specific codes? If not, you may have some codes which may indicate why the monitor is not completing. Again, per the service manual:

"If the initial [fuel tank] target vacuum is exceeded, a system flow fault exists and DTC P1450 (unable to bleed-up fuel tank vacuum) is set. The EVAP Leak Check Monitor will abort and not continue with the leak check portion of the test.

"If the target vacuum is obtained on the fuel tank, the change in the fuel tank vacuum (bleed-up) will be calculated for a calibrated period of time. The calculated change in fuel tank vacuum will be compared to a calibrated threshold for a leak from a hole (opening) of 1.016 mm (0.040 inch) in the Enhanced EVAP system. If the calculated bleed-up is less than the calibrated threshold, the Enhanced EVAP system passes. If the calibrated bleed-up exceeds the calibrated threshold, the test will abort and rerun the test up to three times. "

I expect that "...the test will abort...." is synonomous with "EVAP monitor will not be complete. OBD-II codes of the format P1xyz are manufacturer-specific codes.

-Rod

[97TaurusGuy]

My scan-tool does read Ford specific codes. I think we may be on to something with the MAF sensor though. You will see my initial post was about the CEL being on and the "system too rich" codes were pulle. I changed the air filter and did the procedure that Huney1 described by disconnecting the battery, etc. This seemed to work, and the engine stopped working. But if it is the MAF Sensor, shouldn't the CEL come on like it did before?? So I guess I will take another look at the MAF sensor.
I appreciate all your help guys.
I will let you know my progress.