[butthead88]

Used friend's ODB-II scanner and ScanMaster software, plugged in to my 97 intrepid 3.3l (just pasted 100k miles), run for 20 minutes (local and highway), got some data reading below. Can someone spot some problem from the reading? Please comment. Highly appreciated. Thanks!!!

Description (Units) Min Average Max
-------------------------------------------
03 - Fuel System Status
Fuel System 1 - 2 2 2
Fuel System 2 - 2 2 2
04 - Calculated Load Value (%) 4.31 9.92 28.63
05 - Engine Coolant Temperature （C）92 92.67 93
06 - Short Term Fuel Trim - Bank 1 （%） -3.91 -0.52 1.56
07 - Long Term Fuel Trim - Bank 1 （%） -3.91 1.04 4.69
08 - Short Term Fuel Trim - Bank 2 （%） 0 0.1 2.34
09 - Long Term Fuel Trim - Bank 2 （%） 3.13 5.21 7.81
0B - Intake Manifold Absolute Pressure （kPa）28 48.33 81
0C - Engine RPM (rpm) 605.5 1230.76 2009.25
0D - Vehicle Speed (km/h) 0 34.42 94
0E - Ignition Timing Advance for #1 Cylinder (?) 12.5 27.9 42
0F - Intake Air Temperature (C) 40 45.33 54
11 - Absolute Throttle Position (%) 12.94 17.47 25.1
12 - Commanded Secondary Air Status (-) 0 0 0
14 - Bank 1 - Sensor 1
Oxygen Sensor Output Voltage (V) 0.39 0.75 0.9
Short Term Fuel Trim (%) -4.69 -1.53 3.91
15 - Bank 1 - Sensor 2
Oxygen Sensor Output Voltage (V) 0.15 0.57 0.86
Short Term Fuel Trim (%) 99.21 99.21 99.21
18 - Bank 2 - Sensor 1
Oxygen Sensor Output Voltage (V) 0.1 0.57 0.86
Short Term Fuel Trim (%) -10.16 -0.26 6.25
19 - Bank 2 - Sensor 2
Oxygen Sensor Output Voltage (V) 0.21 0.68 0.88
Short Term Fuel Trim (%) 99.21 99.21 99.21

[MasterTech]

Short Term Fuel Trim (%) -10.16 -0.26 6.25
This looks odd right here, you are subtracting 10% of fuel and then adding 6%. 10% is a little to far off base strategy, but the light won't come on till 25% Then again what kind of issue are you having because the Long Term Fuel Trim is adding fuel on that bank. Long Term Fuel Trim - Bank 2 （%） 3.13 5.21 7.81 I don't get concerned till they exceed 10% when you add both short and long together. Take a reading at idle on bank 2 both LTFT and STFT and then hold the RPM at 2000 for a 60 seconds and take another reading.

[butthead88]

Thanks MASTERTECH for your reply. The report was from the software ScanMaster. We moniterred the vehicle for 20 minutes letting it ran at local and highway. The vehicle is running fine except when parked, when gas paddle released, the engine would idle too low ( as you can see in the report, lowest rpm is 605) for a few seconds, and then idle will back to normal. Any insight?

[MasterTech]

A vacuum gauge should show you between 18 and 21" at idle, kpa is as foreign as a hot girl writing me love letters. Well the first three that come to mind. 1- Dirty throttle body or 2- a problem with the idle air control circuit- valve, wires, or PCM drivers- and I don't see the information on IAC in datastream, and 3-leaking injector(s). Leaking injectors will usually cause an extended crank on cold start, but rather than leaking they could just be giving you a poor spray pattern. Either way you would likely be having poor fuel economy. Again no injector pulse width is showing on datastream to look at. So start off with a good TB and IAC cleaning?

[DrDodge]

I agree on cleaning the TB and Iac

[gardidien]

Do you have a link to the scanmaster software?