rich idle ( sr20det)

Hello guys
I need some help here
my car runs great expect the fact that my idle is a bit on the rich side, the idle can sometime hit 12’s on the wideband, I had it happening for a while now but never really got the time to fix it till now.

I already checked for leak, make it better but I would still like to idle steadily in the 14’s to 16’s if possible (gas ain’t cheap no more).

Assuming that I am coming to a stop, the car will idle in the 14’s , then about a min later , it will progressively hit the 13’s , then 12 and stay there.
I made some adjustment on the safc but as no go, when leaning out the idle furthermore with the safc , the car has now trouble idling.
I am sure there is nothing wrong with my setting and pretty sure it’s something mechanical but I just can figure what…
Can you guys give me suggestion on what to check?

Thank you…

  • Bad temp sensor?
  • Bad 02?
  • Malfunctioning air valve?
  • Bad FPR?

BTW: I checked for code and I have none.

Francis,

It sounds like it could be an 02 problem. The ECU is trying to compensate for a dead and/or improper signal and thereby adding fuel. Could also be a temp sensor but I think that typically results in a poor idle/start.

I think thats a good place to start

Thanks P.T.
Just wondering, what if I were to unplug the O2?
What is suppose to happen?
true say there are 3 wires on the 02 sensor , are they suppose to be power / ground / signal?
Also I have a PLX wideband , can I just use the blue wire and feed a narrow band directly to the ECU? thru the plug and leave the power/ground disconnected? will that even work?

If you unplug the o2 it should throw a code right away. Its not going to harm anything so I would try it and see what happens. Problem is the car will run rich since the ECU wont go into closed loop mode.

Not sure about the 3 wire deal, I would search around

I think technically you can wire use the narrow band simulation from the PLX to the ecu but again Im not sure how well that will work.