jmd1487

Hey just looking for some opinions on this subject. I've noticed that I have some light smoke coming from my exhaust at idle and my A/F is reading 12.0-12.8 at idle no load, does this seem too rich causing the smoke or is there something else going on...

JoeyG

Speed Density Open Loop? If not is your check engine light on all the time?? If not maybe a bad O2 sensor. Ideally you should be 14.7 +/-.2 afr on gasoline.

jmd1487

Yes it is on speed density, if it was a bad O2 would it set a code? My light is always on due to the speed density tune

JoeyG

Yes a bad narrowband O2 sensor can set a code and put you in open loop mode, possibly causing the rich idle. It could also be a bad wideband or uncalibrated sensor issue. Ive run speed density open loop for over a decade in my vette and my idle is 14.4-14.9 depending on outside temperature conditions.

For what its worth you can have the check engine light shut off on nuisance codes such as p103 and others not used in speed density mode.

stevieturbo

Ideal for what ?

Yours is very rich, but no it would not be causing smoke.

Cleanest in terms of emissions is 14.7, hence why OEM's target this to keep cats etc all happy. That isnt to say your engine will always be happiest at this but unless it has silly cams etc there should be little difficulty running at that

jmd1487

Well I talked to my tuner this morning and he said drive it... Guess he is not concerned with it. I however still have my doubts. I'm going to replace the plugs and wires and see if it changes and go from there I guess...

Smoove

Turbo car?

jmd1487

A&A v2si 12lbs w/meth A&A small blower cam stock ls6 with 23k on it, blower has only been on for 1000 miles but it was a used low mile unit

Smoove

eh..I was gonna say maybe turbo related(smoke) but nope.

slow ride

Seems like he just doesn't want to be bothered with it. It would take very little time to clean up the AFR at idle. What is the AFR say if you turn on the AC vs having it off, etc? What AFR does the car run at when on the highway just putzing down the road?

jmd1487

Well my thought was maybe the seal on the supercharger, it's oil fead from the motor.

JoeyG

Out of curiosity, what does your wideband read with the engine off and not running before the car is started/run?

Turpid porpoise

If your blower drain is kinked or clogged it can cause smoke from oil passing the seals if it is anything like a turbo, Im not as fluent in blower behavior.

jmd1487

I will check both of those later today

stevieturbo

Often it will be meaningless, most will read in the lean range, but not all. They arent all the same in that regard.

TXGS507

Mine too runs @ 14.7