I'm going to look at a 2004 F150 this weekend and thought it might be a good idea to take my scan tool and hook it up when we test drive it to check out the live readings, if they will let me. Does anyone know where I might be able to find what the numbers should look like for the live read before I go?

 

After you have it hooked up and calibrated, start motor and go to live, navigate to record freeze frames and it will start recording. You want to do this with the truck warmed up, probably after say a 5/10 mile drive. I would do it on a good highway running about 60 mph steady. It will record 43 freeze frames and going to the middle will probably give you a good average. Say the 20 to 30 frames. Your PID'S should vary some and if you then vary your driving style to record different values you can then compare your PID'S. You're main concern should be what if any codes are there and your I/M tests are completed. Any EVAP test incomplete is a warning of trouble getting it thru tests in your state if any. If your tester graphs you will enjoy watching the Maf and O2 sensor data. Again they should be active on the graphs. Any PID showing spotty or incomplete weak reading would be a malf. Most testers allow you to make 3 test recordings, so you can power test, town test, and whatever you like test. It takes some time to go over all the data, due to the huge amount available to you if you record it all. I like to keep the data to refer to in the future for a problem I am then having. It's like a book of " This is how it was when it was right" LOL If you check out my album you can see the data of my 2011 3.7L. it reads from left to right thru the frames, top to bottom for the different PIDS. Magnify to 200X and easily read the book. Data is in volts, Rpm, temp F. Hg and PSI, even Catz are temps. I didn't want to use all the printer ink doing all the data with the printer.

 

Thank you...I ended up buying one of the trucks I went to look at this weekend, but I will definitely be trying out what you described.