Most of you probably know about this but for those that don't, this is amazing. You can check your DTCs (not OBDII), test your gauges, test your dash bulbs, get a digital display of rpm's, mph's, oil pressure, etc. on your 99-04 mustangs. Here is what you have to do.
Insert key in ignition. Hold odometer trip reset button. While holding button, turn key to "on" position. Do NOT start. Watch odometer. When it says test, release button. Now, every time you push the button another gauge can be monitored. For this example I will use rpm's. Keep pressing button until odometer reads rpm's. Now start the car. It will continuously read rpm's in digital display. To get back to your real odometer all you have to do is hold the rest button for 5 seconds or shut the car off. Give it a try. It is incredible.
Insert key in ignition. Hold odometer trip reset button. While holding button, turn key to "on" position. Do NOT start. Watch odometer. When it says test, release button. Now, every time you push the button another gauge can be monitored. For this example I will use rpm's. Keep pressing button until odometer reads rpm's. Now start the car. It will continuously read rpm's in digital display. To get back to your real odometer all you have to do is hold the rest button for 5 seconds or shut the car off. Give it a try. It is incredible.
My 97 no gots. My brother's 2000 did though, it's pretty cool!