PO172 - CEG Archives

I have a real time scanner but I don't have the manual to tell me how to use it.
I don't understand why I don't get rich on bank 2 also.
Can anybody tell me how to check the system in KOER mode.
I'm trying to avoid the expense of any unnecessary labor or manuals, ect. because I need to sale this car.

What engine, year and mileage? What air filter are you using? Clean the MAF. What scanner is it? You might be able to download instructions or the manual.

Some reasons for P0172 from TSB.

P0172 - System Too Rich (Bank 1) The Adaptive Fuel Strategy continuously monitors fuel delivery hardware. The code sets when the adaptive fuel tables reach a lean calibrated limit.

Fuel System:
�?· Excessive fuel pressure
�?· Leaking/contaminated fuel injectors
�?· Vapor recovery system concern

Base Engine:
�?· Oil overfill
�?· Cam timing concern
�?· Low cylinder compression
�?· Excessive engine wear
Powertrain Control System:
�?· PCM concern

Induction System:
�?· MAF contamination

2000 CSVT, 83,000 miles, paper air filter, Actron CP9145 scanner, and I have cleaned MAF.

www.actron.com has the manual for download (free).

Edit. Direct link
http://www.actron.com/product_detail.php?pid=16150

If you are getting a rich code set on only one bank, you need to look for something that can affect only one bank.

Things to look at:

injectors for that bank. (though would probably lead to a misfire if they weren't operating properly.. note I said PROBABLY)
spark plugs for that bank. Check gap, etc.
faulty O2 sensor on that bank

Things NOT to check, or not LIKELY to cause the problem:

MAF, TB, etc (anything that is before the air-path splits in to seperate banks)

I agree. I'm thinking it may be an injector leaking. I was having the 1/4 tank returnless fuel pump issue and had removed the pump several times in attemps to clean the sock filter and remove the disk screen, which didn't help, so I installed the fsvt pump. During these removals the fuel pressure has been very low. I'm not sure how low because my pressure gauge needs a new seal so I have not bothered with putting it on to check for leak down while the key is off. I remember changing the fuel filter a couple of years ago and the pressure was unbelievable. I thought it was never going to stop spraying!
Is there a way I could use my scanner to determine if an injector is leaking? I already have the manual that Tony linked for me. (Thanks Tony) I believe there is also a manual that is more detailed for around $100 which I don't have just laying around, my kids beat me to it!
I have replaced the lower bank one O2 sensor, still get PO172, so I switched it out with bank two's lower sensor, and I still get PO172.

Originally posted by brett64:
..
I have replaced the lower bank one O2 sensor, still get PO172, so I switched it out with bank two's lower sensor, and I still get PO172.

P0172 has nothing to do with lower O2 sensors. Just plug in your scanner and drive the car for a while then download the info from the scanner. All the info on how to download the P/ID and freeze frame data is in the downloaded manual. Then post the data and more help will be coming. If you can't do that, then send it in for a one hour scan diagnostic and they will be able to tell you if you injectors are bad or whatever.

I replaced the bank 2 sensor because the shop that installed a new clutch, etc. pinched the wire and it was measuring 5.8 ohms. I figured that it was sending a low signal back to the PCM which was richening the fuel mixture then causing the PO172 code. So while I was under the car one day I decided to switch the two.
The freeze frame I have is:
RPM 2713
CALC Load % 12.2
Coolant temp. 183
LT FTRM 1 % -24.2
ST FTRM 1 % -6.3
LT FTRM 2 % -18.8
ST FTRM 2 % -7.0
Veh. speed 45
Fuel sys 1 CLSD
Fuel sys 2 N/A
I don't have a clue what all this means.

Originally posted by brett64:
I replaced the bank 2 sensor because the shop that installed a new clutch, etc. pinched the wire and it was measuring 5.8 ohms. I figured that it was sending a low signal back to the PCM which was richening the fuel mixture then causing the PO172 code. So while I was under the car one day I decided to switch the two.
The freeze frame I have is:
RPM 2713
CALC Load % 12.2
Coolant temp. 183
LT FTRM 1 % -24.2
ST FTRM 1 % -6.3
LT FTRM 2 % -18.8
ST FTRM 2 % -7.0
Veh. speed 45
Fuel sys 1 CLSD
Fuel sys 2 N/A
I don't have a clue what all this means.

I suspect your thermostat is stuck on open and hence keeping the engine cool or ECT sensor is broken (connector/wire broken). The thermostat is supposed to open at 195 F. It appears that it opened much earlier and then the engine went to closed loop. At that time, the engine was still running rich. The PCM usuallly ignores the rich condition when the engine is in open loop but in your case, it was just enough to go to closed loop. If you look at the Bank 2 Long Term Fuel Trim, it is also on the high side. With continued driving, you will also get a P0175 (Bank 2 rich condition). I would check/change the the thermostat and/or ECT sensor.

Thermostat ($12)
http://www.autozone.com/servlet/UiBroker?ForwardPage=/az/cds/en_us/0900823d/80/1b/c8/7d/0900823d801bc87d.jsp

Test the ECT sensor ($17).
http://www.autozone.com/servlet/UiBroker?ForwardPage=/az/cds/en_us/0900823d/80/1b/ca/ba/0900823d801bcaba.jsp

Location of ECT sensor
Check the wiring at the connector first.

Here is a post from Chongo. It highlights the ECT sensor.

Originally posted by chongo:
Did someone call me out.......LOL

here you go.

The thermostat is 188 degree it appears to start opening around that temp. The car warms up quickly and the temp gauge stays near the center or to the cool side of the center.

What degree thermostat should be in this car?

I could not make out the ohm resistance chart for the ECT sensor that is in the Autozone instructions, so I have not checked it yet.

Originally posted by brett64:
..What degree thermostat should be in this car?
...

Stock was 195 F. Some with Zetec I-4 use the 185 F due to the "perceived" overheating. Most Duratec V-6 do not have the "perceived" overheating. If the Duratec overheats, it overheats!

What are the PIDs when the car is running (and warmed up)? Try that and see what they are. It might give more clues.

I am going to put a new thermostat in since I have it out and can get a new one so cheap. Just to see if that changes anything.
What PIDS are you talking about, all of them? Do they change when driving or stay the same as idling?

What you have posted are freeze frame data (at the time, the P0172 code was recorded in the PCM). IIRC, the CP9145 is capable of real time scanning and records the parameters for a couple of minutes (maybe 15?) while driving. You can download the data on a printer or write it down. Then you can see what is happening at various RPM and speeds.

I can't drive the car right now to monitor whats going on, but I will in a few days and post what comes up.

I put a new 195 F thermostat in and cleared the codes. The car stalled at a stop sign but restarted. It was acting like it was starving for fuel for a moment then began to run a little better but still not like it should. After driving about 5 miles code P1132 was sent (Mfg fuel air mixture out of range) or something like that. Here is the freeze frame:
RPM 3094
Calc load % 20.4
coolant temp 189 F
LT FTRM1 % 0.0
ST FTRM1 % -20.3
LT FTRM2 % 0.0
ST FTRM2 % -18.0
Speed 52
Fuel sys CLSD
I cleared the codes again and drove about 18 miles. This time no stalling but still sluggish. As I drove I noticed the fuel sys. was going from open to closed. When I come down a hill and let totally off the throddle the fuel sys. opens when I press the pedal lightly the system closes when I press harder the system opens again. Is this normal? However no codes were sent during this drive cycle.
I have not learned how to download the info. for the scanner yet.

P1132 Insufficient switching Bank 1 Upper Sensor/Rich

Have you tested the ECT sensor yet?

You should also test the Bank 1 (firewall side) Upper O2 Sensor.
http://www.autozone.com/servlet/UiBroker?ForwardPage=/az/cds/en_us/0900823d/80/1b/ca/83/0900823d801bca83.jsp

Originally posted by Ray:
If you are getting a rich code set on only one bank, you need to look for something that can affect only one bank.

Things to look at:
......faulty O2 sensor on that bank .......

Bank 1 Upper O2 sensor how to.
http://www.contour.org/ubbthreads/showflat.php?Cat=&Board=v6maint&Number=1023736&Forum=v6maint&Words=replace%20o2&Match=And&Searchpage=0&Limit=2500&Old=allposts&Main=1023736&Search=true#Post1023736

From TSB,

P1132 - Lack of HO2S-11 Switch, Indicates Rich. When an HO2S sensor indicates rich at the end of a test, the system is trying to correct for an over-rich condition. The code is set when the fuel control system no longer detects switching for a calibrated amount of time.

Electrical:
�?· Short to VPWR or VREF in harness or HO2S
�?· HO2S circuit shorted to Ground
�?· Water in harness connector
�?· Open circuit
�?· Corrosion or poor mating terminals and wiring
�?· Damaged HO2S
�?· Damaged PCM (other DTCs should be present)

Fuel System:
�?· Excessive fuel pressure (stuck fuel pressure regulator, restricted fuel return lines, etc.)
�?· Leaking/contaminated fuel injectors or fuel pressure regulator
�?· Low fuel pressure or running out of fuel (fuel pump concern, fuel supply line restrictions, low fuel level, etc.)
�?· Vapor recovery system (stuck VMV, etc.)

Induction System:
�?· MAF contamination
�?· Air leaks between MAF and throttle plate
�?· PCV system / Other vacuum leaks
�?· Improperly seated engine oil dipstick

EGR System:
�?· Leaking gasket
�?· Stuck EGR valve / Leaking diaphragm or EVR

Base Engine:
�?· Oil overfill
�?· Incorrect cylinder compression
�?· Exhaust leaks before or near the HO2S
�?· Secondary air stuck on

I drove the car again for half an hour for a total of 35+ miles and still no codes were sent. The car ran great this time.
I left out one thing in my last post about the fuel system going closed to open(1) I read the fuel system will go to open1 in these conditions.
Is there not a code for the bank 1 HO2S?
I think I will drive some more to see if the car will send any more codes.
How many miles do you have to drive before the car is ready for an emissions test?

"Is there not a code for the bank 1 HO2S?"
P1132 is Bank 1 Upper Sensor (a.k.a. HO2S11) code.

"How many miles do you have to drive before the car is ready for an emissions test?"
It is not miles. It is the OBD II cycle you have to go through.
This will describe the Inspection/Maintenance monitors and the OBD II drive cycle.
http://www.obdii.com/drivecycleford.html

I did what the link said, to complete the I/M readiness. The EVAP, Catalyst, HO2S, O2S are still not ready. This was about the 6th or 7th drive cycle and still no codes have been sent. The car ran normal during this last drive cycle.
I've spent too much money on this car. I bought it to help a family member. Things didn't work out now I just need to sale it so I can try to get my money back. $7,000 not counting ins, tag, and labor.
Needless to say right now I am hoping the thermostat was too cool and causing the problems.

Originally posted by brett64:
..I could not make out the ohm resistance chart for the ECT sensor that is in the Autozone instructions, so I have not checked it yet.

Click on the chart and it opens up in a different window. Note that some OBD II tests will not run if the ECT does not send a correct signal. So, test the ECT sensor.

I found a chart in my Contour repair manual. The sensor seemed to be really close to spec. It was hard to hold it in the 200+ F water and check but the ohms came down to 2.0 at that temp and was around 33 ohms when I first removed it.
I drove the car again this evening and P0172 code came back.

Did you get a chance to test the Bank 1 (firewall side) Upper O2 sensor?

Well my cheesy manual says testing an O2 sensor is beyond the scope of the DIY. Two of the terminals on the sensor measured 3.8 ohms. The other two didn't read anything. Other than that I don't know how to test them.

From previous post with autozone link on testing O2 sensor.

"Disconnect the HO2S.

Measure the resistance between PWR and GND terminals of the sensor. Resistance should be approximately 6 ohms at 68�?°F (20�?°C). If resistance is not within specification, the sensor's heater element is faulty.

With the HO2S connected and engine running, measure the voltage with a Digital Volt-Ohmmeter (DVOM) between terminals HO2S and SIG RTN (GND) of the oxygen sensor connector. Voltage should fluctuate between 0.01-1.1 volts. If voltage fluctuation is slow or voltage is not within specification, the sensor may be faulty."

Originally posted by Brett64:
Well my cheesy manual says testing an O2 sensor is beyond the scope of the DIY. Two of the terminals on the sensor measured 3.8 ohms. The other two didn't read anything. Other than that I don't know how to test them.

The two terminals that did show resistance are the heater elements.

The other two are the sensor itself which is not a resistance-type device.

If you really want to test it, remove it, connect a voltmeter to the two sensor elements, and heat the tip with a propane torch while watching the voltmeter. A good sensor will start generating voltage (up to aroun .8 or .9 Vdc when it gets hot.

Steve

I will be busy today, but I should be able to check tomorrow. I want to check the lower sensors as well to see how much voltage they make.

Originally posted by Brett64:
I will be busy today, but I should be able to check tomorrow. I want to check the lower sensors as well to see how much voltage they make.

The downstream sensors aren't an issue here unless you just wish to indulge curiosity.

Steve

I checked the top two O2 sensors they both climbed up to .8 vdc as they heated up.
I still have some concern about the fuel pressure dropping. I have installed the FSVT pump but it still has trouble when the tank is 1/4 or lower. It seems to me that the gas runs away from the pickup when hard cornering or going up a hill under heavy acceleration. Could this somehow be affecting the PCM calculations? Is the tank suppose to have baffles to stop the fuel from running away? Is there other reasons for this condition like the inertia switch malfunctioning?
Now where do I go from here?

Originally posted by Brett64:
.. I have installed the FSVT pump but it still has trouble when the tank is 1/4 or lower. ....
Now where do I go from here?

Did you remove the fuel sock?

I removed the disc filter and cleaned the sock with carb cleaner from the inside out.
I was afraid to run it without the sock filter. Did anybody ever find someplace to buy new sock filters?

Originally posted by Brett64:
I removed the disc filter and cleaned the sock with carb cleaner from the inside out.
I was afraid to run it without the sock filter. Did anybody ever find someplace to buy new sock filters?

It may have clogged up again. The fuel filter should take care of any sediment that entered and left the fuel tank.

I completly cleaned everything out of the tank. The first time I drove it after the install it acted up again when the tank got low.
Is the pump basket suppose to hold fuel to work like a baffle?
Maybe this is the problem. I had read a thread about the returnless system problem, where the guy bought the Contour replacement pump instead of the FSVT pump and didn't have any more trouble.
The wires that plug into the pump were overheated at some point, I had to splice in the new pump wires to replace the old ones. Have you ever heard of this problem, or is that normal?

Fuel System:
�?· Excessive fuel pressure
�?· Leaking/contaminated fuel injectors
�?· Vapor recovery system concern

I checked for fuel pressure at the test port after the car had not run all day and no pressure was present. That is why I think I have a leaking injector. How can I test my injectors?

I sperated the fuel line at the fuel rail and pressure tested the main line to the tank, pump, etc. the pressure dropped from 42 psi to 30 psi in an hour and a half. Meanwhile I had another gauge on the fuel rail testing the injectors. They held 42 psi for the whole time. So I think the injectors are fine. Any other suggestions would be greatly appreciated.

I took my car to the stealership for diagnostics. They told me the MAF voltage was off and was the wrong part number for my car and could not go any further without replacing it for $400+ so I went and got it stopped by Autozone on the way home and bought a remanufactured MAF. Needless to say my fuel trim on bank 1 is still 7-9% lower than bank 2.
My upper O2 sensors are switching well (even the stealearship said so). The injectors are holding pressure well. What else could cause the bank one fuel trims to be so much lower. When I switched the two upper O2 sensors they were chalked as if the engine is really running lean.
What's really odd is my brother has a 24v 2000 Taurus with the same code P0172.