here's some useful sensor faults/symptoms that can help narrow down an issue

O2 SENSOR FAULTY
SYMPTOM: Rough idle usually cold (Closed loop) and jerky (surging)cruising acceleration.
WHY: Because the ECU isnt getting a proper reading anymore and the rough idle and surging is because the ecu is inlimp mode and flooding the car with extra fuel to protect it. Surging problems 9 out of 10 times are always fuel related.
sometimes faulty 02 sensor does not throw a CEL code. Well not in the begining anyway.


KNOCK SENSOR FAULTY
SYMPTOM: Hard to notice but not the smoothest acceleration. Biggest symptom is on the highway when you accelerate under load like 4th or 5th gear the car jerks and surges. Anything below it drives normal.
WHY: Because the knock sensor is giving the wrong signal or no signal so therefore once again ECU runs in SAFE mode and protects the car by retarding timing and running safe fuel maps under full load driving conditions.



AFM SENSOR FAULTY
Symptom:Rough idle all the time. Rough stuttering acceleration aka misfiring. Poor acceleration through through the entire rev range. Pinging because its running lean and this is the biggest cause of engine failure due to faulty AFM.
WHY:The ECU has a close relationship with the AFM like a mother and son from Tasmania kinda relationship. They dont question each others actions. The AFM obviously gives the ECU readings. When the AFM fails the ecu is still assuming its giving correct readings while the car is accelerating. Only if the car starts to stall or really bad rough idle the ECU then tries to compensate. Thats why you can test when you have a faulty AFM. Rough idle and disconnect the AFM. If it still runs then its AFM because the ecu has compensated for dodge idle AFM readings. If it does stall when you disconnect AFM then chances it isnt AFM.
Best way is to always test.


Faulty TPS
SYMPTOM: Rough accelaration through the range. Or a particular rev range or throttle range displays funny behaviour because there is a dead or worn spot on the TPS.
WHY: Same thing ECU gets incorrect voltage readings from the TPS. ECU doesnt see voltage at all sometimes and one again usually runs into safe mode and runs extra rich for protection. Hmm sounds like while the car is starting up you hit the F8 key right? lol
If you have a Multimetre or AVCR hooked up you can read the TPS. On closed throttle it should read around .44volts or so. On WOT it should read 3.5 volts I believe.