Greetings,
I have a 1999 Ranger, 124K, EDIT: V6 4.0L 2WD runs good. However on cold days.. below 30'F I get pending codes PO171 and PO174 banks 1 and 2 too lean. Then next cold day. MIL on. Both codes show up at same time. I cleared them 3 times.

I have cleaned the MAF senor, cleaned air filter, currently running seaform cleaner in gas (hasnt had a chance to work yet)

I have read many forums. I tested for vaccum links by waiting for a good cold day.. 23'F and spaying Carb cleaner on suspected areas... then just spraying it all over... no change in idle.

Here is the data from my scan tool.

Recorded Data
MIL STATUS OFF
ABSLT TPS % 18.4
ENG SPEED RPM 942
CALC LOAD % 39.6
MAF FLOW GR/SE 6.19
COOLANT �F 163
IAT �F 73
IGN ADVANCE DE 14.0
ST FTRM1 % 0.7
LT FTRM1 % 6.2
ST FTRM2 % 0.7
LT FTRM2 % 2.3
VEH SPEED MPH 0
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
O2S11 V 0.040
ST FTRM11 % 3.9
O2S12 V 0.000
O2S21 V 0.560
ST FTRM21 % 0.8
OBD2 STAT CA
Frame -5 Time -3.5

MIL STATUS OFF
ABSLT TPS % 18.4
ENG SPEED RPM 935
CALC LOAD % 38.4
MAF FLOW GR/SE 6.42
COOLANT �F 163
IAT �F 73
IGN ADVANCE DE 14.0
ST FTRM1 % 5.4
LT FTRM1 % 6.2
ST FTRM2 % 1.5
LT FTRM2 % 2.3
VEH SPEED MPH 0
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
O2S11 V 0.235
ST FTRM11 % 3.9
O2S12 V 0.000
O2S21 V 0.650
ST FTRM21 % -2.2
OBD2 STAT CA
Frame -4 Time -2.8

MIL STATUS OFF
ABSLT TPS % 18.4
ENG SPEED RPM 980
CALC LOAD % 38.0
MAF FLOW GR/SE 6.37
COOLANT �F 163
IAT �F 73
IGN ADVANCE DE 14.5
ST FTRM1 % 3.9
LT FTRM1 % 6.2
ST FTRM2 % -2.2
LT FTRM2 % 2.3
VEH SPEED MPH 0
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
O2S11 V 0.665
ST FTRM11 % 0.8
O2S12 V 0.000
O2S21 V 0.685
ST FTRM21 % -2.2
OBD2 STAT CA
Frame -3 Time -2.1

MIL STATUS OFF
ABSLT TPS % 18.4
ENG SPEED RPM 943
CALC LOAD % 39.6
MAF FLOW GR/SE 6.33
COOLANT �F 161
IAT �F 73
IGN ADVANCE DE 14.0
ST FTRM1 % -1.0
LT FTRM1 % 6.2
ST FTRM2 % 3.1
LT FTRM2 % 2.3
VEH SPEED MPH 0
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
O2S11 V 0.060
ST FTRM11 % 6.2
O2S12 V 0.000
O2S21 V 0.265
ST FTRM21 % 3.1
OBD2 STAT CA
Frame -2 Time -1.4

MIL STATUS OFF
ABSLT TPS % 18.4
ENG SPEED RPM 1009
CALC LOAD % 38.0
MAF FLOW GR/SE 6.37
COOLANT �F 161
IAT �F 73
IGN ADVANCE DE 14.0
ST FTRM1 % 0.7
LT FTRM1 % 6.2
ST FTRM2 % 0.7
LT FTRM2 % 2.3
VEH SPEED MPH 0
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
O2S11 V 0.105
ST FTRM11 % 3.1
O2S12 V 0.000
O2S21 V 0.675
ST FTRM21 % -2.2
OBD2 STAT CA
Frame -1 Time -0.7

MIL STATUS OFF
ABSLT TPS % 18.4
ENG SPEED RPM 992
CALC LOAD % 38.0
MAF FLOW GR/SE 6.33
COOLANT �F 161
IAT �F 73
IGN ADVANCE DE 16.0
ST FTRM1 % 1.5
LT FTRM1 % 6.2
ST FTRM2 % -3.4
LT FTRM2 % 2.3
VEH SPEED MPH 0
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
O2S11 V 0.655
ST FTRM11 % -1.0
O2S12 V 0.000
O2S21 V 0.670
ST FTRM21 % -1.0
OBD2 STAT CA
Frame 0 Time 0.0

MIL STATUS OFF
ABSLT TPS % 18.4
ENG SPEED RPM 993
CALC LOAD % 37.6
MAF FLOW GR/SE 6.28
COOLANT �F 161
IAT �F 73
IGN ADVANCE DE 15.5
ST FTRM1 % 2.3
LT FTRM1 % 6.2
ST FTRM2 % -1.0
LT FTRM2 % 2.3
VEH SPEED MPH 0
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
O2S11 V 0.720
ST FTRM11 % 0.8
O2S12 V 0.005
O2S21 V 0.195
ST FTRM21 % 3.1
OBD2 STAT CA
Frame 1 Time 0.8

MIL STATUS OFF
ABSLT TPS % 18.4
ENG SPEED RPM 1012
CALC LOAD % 37.6
MAF FLOW GR/SE 6.33
COOLANT �F 161
IAT �F 73
IGN ADVANCE DE 15.5
ST FTRM1 % 0.8
LT FTRM1 % 6.2
ST FTRM2 % -1.0
LT FTRM2 % 2.3
VEH SPEED MPH 0
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
O2S11 V 0.215
ST FTRM11 % 1.5
O2S12 V 0.005
O2S21 V 0.160
ST FTRM21 % 1.5
OBD2 STAT CA
Frame 2 Time 1.5

MIL STATUS OFF
ABSLT TPS % 20.7
ENG SPEED RPM 836
CALC LOAD % 46.2
MAF FLOW GR/SE 8.96
COOLANT �F 161
IAT �F 73
IGN ADVANCE DE 17.0
ST FTRM1 % 5.4
LT FTRM1 % 4.6
ST FTRM2 % 5.4
LT FTRM2 % -1.0
VEH SPEED MPH 1
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
O2S11 V 0.655
ST FTRM11 % 3.1
O2S12 V 0.010
O2S21 V 0.460
ST FTRM21 % 6.2
OBD2 STAT CA
Frame 3 Time 2.2

MIL STATUS OFF
ABSLT TPS % 18.8
ENG SPEED RPM 877
CALC LOAD % 44.3
MAF FLOW GR/SE 7.02
COOLANT �F 161
IAT �F 73
IGN ADVANCE DE 17.0
ST FTRM1 % 3.9
LT FTRM1 % 5.4
ST FTRM2 % 3.9
LT FTRM2 % 2.3
VEH SPEED MPH 4
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
O2S11 V 0.125
ST FTRM11 % 7.0
O2S12 V 0.040
O2S21 V 0.625
ST FTRM21 % 2.3
OBD2 STAT CA
Frame 4 Time 2.9

MIL STATUS OFF
ABSLT TPS % 18.4
ENG SPEED RPM 841
CALC LOAD % 42.3
MAF FLOW GR/SE 7.90
COOLANT �F 161
IAT �F 73
IGN ADVANCE DE 17.5
ST FTRM1 % 7.0
LT FTRM1 % 3.9
ST FTRM2 % 10.9
LT FTRM2 % 0.8
VEH SPEED MPH 0
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
O2S11 V 0.270
ST FTRM11 % 7.8
O2S12 V 0.065
O2S21 V 0.150
ST FTRM21 % 8.5
OBD2 STAT CA
Frame 5 Time 3.5

MIL STATUS OFF
ABSLT TPS % 20.7
ENG SPEED RPM 995
CALC LOAD % 41.9
MAF FLOW GR/SE 12.15
COOLANT �F 161
IAT �F 73
IGN ADVANCE DE 18.0
ST FTRM1 % 7.8
LT FTRM1 % 4.6
ST FTRM2 % 6.2
LT FTRM2 % 2.3
VEH SPEED MPH 6
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
O2S11 V 0.500
ST FTRM11 % 7.0
O2S12 V 0.075
O2S21 V 0.525
ST FTRM21 % 3.1
OBD2 STAT CA
Frame 6 Time 4.2

MIL STATUS OFF
ABSLT TPS % 25.8
ENG SPEED RPM 1480
CALC LOAD % 52.5
MAF FLOW GR/SE 21.34
COOLANT �F 161
IAT �F 71
IGN ADVANCE DE 18.5
ST FTRM1 % 2.3
LT FTRM1 % 3.9
ST FTRM2 % 0.7
LT FTRM2 % -3.4
VEH SPEED MPH 11
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
O2S11 V 0.000
ST FTRM11 % 7.8
O2S12 V 0.070
O2S21 V 0.070
ST FTRM21 % 10.1
OBD2 STAT CA
Frame 7 Time 4.9

MIL STATUS OFF
ABSLT TPS % 28.2
ENG SPEED RPM 1795
CALC LOAD % 50.1
MAF FLOW GR/SE 21.34
COOLANT �F 163
IAT �F 69
IGN ADVANCE DE 19.0
ST FTRM1 % 0.0
LT FTRM1 % 5.4
ST FTRM2 % 0.0
LT FTRM2 % 3.9
VEH SPEED MPH 14
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
O2S11 V 0.390
ST FTRM11 % 3.9
O2S12 V 0.520
O2S21 V 0.715
ST FTRM21 % 0.0
OBD2 STAT CA
Frame 8 Time 5.6

MIL STATUS OFF
ABSLT TPS % 21.1
ENG SPEED RPM 1145
CALC LOAD % 37.6
MAF FLOW GR/SE 8.59
COOLANT �F 163
IAT �F 69
IGN ADVANCE DE 19.5
ST FTRM1 % -1.0
LT FTRM1 % 3.9
ST FTRM2 % 0.8
LT FTRM2 % -4.6
VEH SPEED MPH 14
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
O2S11 V 0.070
ST FTRM11 % 7.8
O2S12 V 0.045
O2S21 V 0.540
ST FTRM21 % 6.2
OBD2 STAT CA
Frame 9 Time 6.3

MIL STATUS OFF
ABSLT TPS % 30.9
ENG SPEED RPM 2034
CALC LOAD % 51.3
MAF FLOW GR/SE 28.41
COOLANT �F 163
IAT �F 66
IGN ADVANCE DE 20.0
ST FTRM1 % 3.1
LT FTRM1 % 4.6
ST FTRM2 % 5.4
LT FTRM2 % 3.9
VEH SPEED MPH 18
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
O2S11 V 0.520
ST FTRM11 % 3.1
O2S12 V 0.655
O2S21 V 0.795
ST FTRM21 % -4.6
OBD2 STAT CA
Frame 10 Time 7.0

MIL STATUS OFF
ABSLT TPS % 19.2
ENG SPEED RPM 1307
CALC LOAD % 31.7
MAF FLOW GR/SE 7.11
COOLANT �F 165
IAT �F 64
IGN ADVANCE DE 21.0
ST FTRM1 % -8.0
LT FTRM1 % 5.4
ST FTRM2 % -6.3
LT FTRM2 % 2.3
VEH SPEED MPH 16
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
O2S11 V 0.005
ST FTRM11 % -3.4
O2S12 V 0.680
O2S21 V 0.070
ST FTRM21 % 0.0
OBD2 STAT CA
Frame 11 Time 7.6

MIL STATUS OFF
ABSLT TPS % 18.4
ENG SPEED RPM 1106
CALC LOAD % 35.6
MAF FLOW GR/SE 6.69
COOLANT �F 163
IAT �F 64
IGN ADVANCE DE 21.0
ST FTRM1 % -4.6
LT FTRM1 % 6.2
ST FTRM2 % -4.9
LT FTRM2 % 2.3
VEH SPEED MPH 4
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
O2S11 V 0.030
ST FTRM11 % 1.5
O2S12 V 0.665
O2S21 V 0.210
ST FTRM21 % 1.5
OBD2 STAT CA
Frame 12 Time 8.3

MIL STATUS OFF
ABSLT TPS % 30.5
ENG SPEED RPM 1751
CALC LOAD % 63.9
MAF FLOW GR/SE 28.60
COOLANT �F 163
IAT �F 62
IGN ADVANCE DE 21.5
ST FTRM1 % 2.3
LT FTRM1 % 4.6
ST FTRM2 % 0.7
LT FTRM2 % 1.5
VEH SPEED MPH 8
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
O2S11 V 0.200
ST FTRM11 % 0.0
O2S12 V 0.160
O2S21 V 0.585
ST FTRM21 % 0.8
OBD2 STAT CA
Frame 13 Time 9.0

MIL STATUS OFF
ABSLT TPS % 26.2
ENG SPEED RPM 1378
CALC LOAD % 50.1
MAF FLOW GR/SE 18.75
COOLANT �F 165
IAT �F 62
IGN ADVANCE DE 22.0
ST FTRM1 % 2.3
LT FTRM1 % 5.4
ST FTRM2 % 4.6
LT FTRM2 % 4.6
VEH SPEED MPH 9
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
O2S11 V 0.495
ST FTRM11 % 4.6
O2S12 V 0.080
O2S21 V 0.145
ST FTRM21 % 9.3
OBD2 STAT CA
Frame 14 Time 9.7

MIL STATUS OFF
ABSLT TPS % 43.1
ENG SPEED RPM 2741
CALC LOAD % 79.2
MAF FLOW GR/SE 69.40
COOLANT �F 167
IAT �F 60
IGN ADVANCE DE 15.0
ST FTRM1 % 9.3
LT FTRM1 % 3.9
ST FTRM2 % 12.5
LT FTRM2 % 4.6
VEH SPEED MPH 31
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
O2S11 V 0.835
ST FTRM11 % 1.5
O2S12 V 0.675
O2S21 V 0.715
ST FTRM21 % 5.4
OBD2 STAT CA
Frame 15 Time 10.4

MIL STATUS OFF
ABSLT TPS % 59.2
ENG SPEED RPM 4013
CALC LOAD % 93.7
MAF FLOW GR/SE108.16
COOLANT �F 167
IAT �F 53
IGN ADVANCE DE 14.5
ST FTRM1 % -3.4
LT FTRM1 % 3.1
ST FTRM2 % -7.7
LT FTRM2 % -4.9
VEH SPEED MPH 45
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
O2S11 V 0.660
ST FTRM11 % -8.0
O2S12 V 0.720
O2S21 V 0.070
ST FTRM21 % 0.7
OBD2 STAT CA
Frame 16 Time 11.1

MIL STATUS OFF
ABSLT TPS % 18.4
ENG SPEED RPM 1183
CALC LOAD % 40.0
MAF FLOW GR/SE 8.31
COOLANT �F 167
IAT �F 53
IGN ADVANCE DE 25.0
ST FTRM1 % 1.5
LT FTRM1 % 4.6
ST FTRM2 % 3.1
LT FTRM2 % 0.7
VEH SPEED MPH 42
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
O2S11 V 0.865
ST FTRM11 % -1.0
O2S12 V 0.060
O2S21 V 0.790
ST FTRM21 % -4.6
OBD2 STAT CA
Frame 17 Time 11.8

MIL STATUS OFF
ABSLT TPS % 18.4
ENG SPEED RPM 1345
CALC LOAD % 30.1
MAF FLOW GR/SE 6.97
COOLANT �F 167
IAT �F 55
IGN ADVANCE DE 25.5
ST FTRM1 % 0.8
LT FTRM1 % 3.1
ST FTRM2 % 6.2
LT FTRM2 % -3.4
VEH SPEED MPH 38
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
O2S11 V 0.755
ST FTRM11 % 0.7
O2S12 V 0.080
O2S21 V 0.840
ST FTRM21 % 3.9
OBD2 STAT CA
Frame 18 Time 12.4

MIL STATUS OFF
ABSLT TPS % 25.4
ENG SPEED RPM 1576
CALC LOAD % 44.7
MAF FLOW GR/SE 17.09
COOLANT �F 170
IAT �F 55
IGN ADVANCE DE 26.5
ST FTRM1 % 1.5
LT FTRM1 % 4.6
ST FTRM2 % -1.0
LT FTRM2 % 1.5
VEH SPEED MPH 35
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
O2S11 V 0.745
ST FTRM11 % -4.9
O2S12 V 0.585
O2S21 V 0.560
ST FTRM21 % 0.8
OBD2 STAT CA
Frame 19 Time 13.1

MIL STATUS OFF
ABSLT TPS % 29.4
ENG SPEED RPM 1896
CALC LOAD % 53.7
MAF FLOW GR/SE 26.29
COOLANT �F 170
IAT �F 53
IGN ADVANCE DE 27.0
ST FTRM1 % 3.9
LT FTRM1 % 6.2
ST FTRM2 % 2.3
LT FTRM2 % 5.4
VEH SPEED MPH 34
FUEL SYS 1 CLSD
FUEL SYS 2 N/A
O2S11 V 0.140
ST FTRM11 % 3.9
O2S12 V 0.620
O2S21 V 0.215
ST FTRM21 % 3.9
OBD2 STAT CA
Frame 20 Time 13.8


Rob D.

 

Didn't say what size engine is in it.

 

Added the missing info

Rob D.

 

I hjad the same problem recently, I noticed that there is a 90 degree 5/8 hose that had collapsed and split, was underneath the radiator hose by the valve cover, sees to be a common problem. I sprayed it 3 or 4 times before I found it.

 

If your engine is a 4.0 OHV You need new upper intake o-ring gaskets. 3 required.

 

Have the 4.0 EFI.

 

I checked this hose, looks good.. However... I think it might be the oil cap. I never sprayed anything directly on the oil cap. Its the type that has the racheting (not sure what its called) to keep from over tightening.. seems to be a bit liberal. The first time the check engine light came on was just a few days after an oil change at the quicky place. I checked the national weather data for temp data.. it had just started getting cold around that time. I cleaned the cap and put it on as tight as I can... well shell see... Next cold cold weather is later this week... see if I get any pending codes.

Rob D.

 

Just checking back in.... we had last few days with cold weather.. one day was the coldest since I had the problem, low was 17'F as of today.. there are no pending codes.... so it was the #%@&# OIL CAP!

code reader and message boards saved me $$$. Parts place was sure it was the $100 Mass air flow sensor. ;-)

Rob D>