# rich idle ( sr20det)

**URL:** <https://forums.speedlife.net/t/rich-idle-sr20det/114799>\
**Category:** SON240sx Automotive\
**Created:** [April 18, 2008, 7:47pm UTC](https://forums.speedlife.net/t/rich-idle-sr20det/114799 "2008-04-18T19:47:18Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![absolum](https://avatars.discourse-cdn.com/v4/letter/a/e47c2d/32.png) [@absolum](https://forums.speedlife.net/u/absolum)\
**Post date:** [April 18, 2008, 7:47pm UTC](https://forums.speedlife.net/t/rich-idle-sr20det/114799/1 "2008-04-18T19:47:18Z")

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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.

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**Author:** ![KoukiS14](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/koukis14/32/5522_2.png) [@KoukiS14](https://forums.speedlife.net/u/KoukiS14)\
**Post date:** [April 20, 2008, 8:49am UTC](https://forums.speedlife.net/t/rich-idle-sr20det/114799/2 "2008-04-20T08:49:41Z")

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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

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**Author:** ![absolum](https://avatars.discourse-cdn.com/v4/letter/a/e47c2d/32.png) [@absolum](https://forums.speedlife.net/u/absolum)\
**Post date:** [April 20, 2008, 10:58pm UTC](https://forums.speedlife.net/t/rich-idle-sr20det/114799/3 "2008-04-20T22:58:49Z")

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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?

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**Author:** ![KoukiS14](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/koukis14/32/5522_2.png) [@KoukiS14](https://forums.speedlife.net/u/KoukiS14)\
**Post date:** [April 21, 2008, 7:33am UTC](https://forums.speedlife.net/t/rich-idle-sr20det/114799/4 "2008-04-21T07:33:01Z")

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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.