I recently purchased a '99 Sonata. It had a check engine light when I bought
it (not sure for how long).
It was running pretty well when I first got it but now has developed massive
idling & transmission shifting problems. Idles very rough (dieseling fairly
pronounced at ildi/low speed, 3-4k+ RPM for extended periods before
shifting, at 55-65 MPH cruising speed if car does manage to shift there is a
noticeable vibration from the engine unless it is allowed to downshift).
Ran diagnostics and got the following results:
P0171 - System Too Lean (Bank 1)
P0125 - Clsd Loop Fuel Ctrl, Insufficient Coolant Temp
P0303 - Cylinder 3 Misfire Detected
P0705 - Trans Range Sensor Circuit Malfunction
Cleared the codes and drove until new check engine light came on:
Only P0171 - System Too Lean (Bank 1) returned.
Repeated clear and recheck same results.
So I gues my questions are:
What are the symptoms of a "Trans Range Sensor Circuit Malfunction" and
could it been cuasing the problems I described?
Is it possible that the sensor (circuit) is the primary culprit despite the
fact that the code hasn't returned on the diagnostic test?
Thanks in advance for your assistance.