I have a weird issue on my 2004 Mazda 3 2.3L (non-turbo, cable throttle), where letting go of the throttle causes the engine to shudder and drop RPM harshly, but ONLY when the engine has warmed up.
I have taken a screenshot of my timing advance while driving and the issue occurs, and this is what I have recorded:
My current suspicion is a faulty Crankshaft Position Sensor, which I will be replacing soon. I noticed it is covered in oil:
Thanks for the replies! It could be a coil. Would this show a CEL? I have no CEL which has really made things more difficult.
I also got confused with the throttle body situation. It’s definitely cable, and realised that only Australians got a cable throttle on the earlier models. So weird lol
So… I tried the screw driver tip and it passed the test.
Now weird issue, I was cleaning the sensors with some contact cleaner, and I took the car for a test drive and the pre-cat O2 sensor seems to have died and pulled a P0132 code.
Ive checked and changed fuses, and nothing seems to have changed. I’ve tried clearing the code but it keeps coming back, so I’ve ordered a new O2 sensor.
I didnt think the contact cleaner was conductive, but it said on the bottle to not use it on an energised contact, which was probably my mistake. Doesn’t matter, it was an old O2 sensor anyway.
I guess my next update is when i replace the crank and o2 sensor haha