Scanner parameters, which ones are most useful?

[Lignite]

So I just pulled the trigger on a scanner (OBDlink with ScanXL software) to help find the miss on my '97 5.0. But as it turns out there seems to be many many things to moniter. Would someone have a recomendation on what parameters I should moniter to help diagnose problems? Even if its a general idea, I'm new to this and am finding it difficult to learn where and how to get started. What things do you watch for when datalogging?

I will probably have to start another threat about o2 sensors, and what the scanner is telling me about them.


Thanks for any information, my apologies for being vague. It seems I don't have enough mechanical knowledge to even know the correct questions to ask.

 

[2000StreetRod]

Misfire parameters

In my opinion, the available scanner parameters are not real helpful to isolate a cylinder misfire. The pre-cat O2 sensors and fuel trims may help determine if one bank is more rich than the other which could be caused by a plug not firing causing the misfire. I think the OBD-II DTCs are the most helpful since OBD monitors each cylinder in real time. Do you get any DTCs associated with your misfire?

Misfire is reported when low power is detected. It could be due to ignition, fuel injection or poor compression in that order of likelyhood IMO. There's a special chip in the PCM to monitor the ignition (used to be in the external Ignition Control Module). Fuel injection related misfire for just one cylinder could be due to clogged injector or bad injector (electrical or mechanical). Poor compression could be due to worn rings, burned valves, sticking valves, blown head gasket or cracked head.

I usually record ECT, rpm, IAT, STFT, LTFT, O2s front & rear, TPS, MAFS and ignition timing every time with my Windows based Dyno-Scan.