AFR Problem

[1gDSM4g63]

The wideband is reading lean at all times even when the car is at idle. No matter how I adjust the SAFC it's always lean even though I tell it's running super rich. And if I drive the car it will die down and 20-30 mph.

I'm flat-out confused. There no leaks around the MAF. Could it possibility be a bad MAF or o2 sensor? And why does it die down even if it's running super rich?

 

[yokotabrat]

What do you mean by die down? Does it stutter? At WOT, or at partial throttle. What's the wideband reading for A/F ratio?

Do you have a logger? Can you read your low/medium/high fuel trims? That should help give you an idea if the wideband is reading correctly.

 

[1992awdlaser]

What exactly is it reading at idle and cruise?

 

[1gDSM4g63]

What do you mean by die down? Does it stutter? At WOT, or at partial throttle. What's the wideband reading for A/F ratio?

Do you have a logger? Can you read your low/medium/high fuel trims? That should help give you an idea if the wideband is reading correctly.

It stuttered at partial throttle and the wideband always is at 19+ and the PLX-300 always displays lean.

I'll update the readings from my datalogger later.

 

[kmoore]

What kind of wideband do you have?

 

[1gDSM4g63]

What kind of wideband do you have?

PLX-300. Even though it says lean I can tell it's running super rich. I can smell gas fumes from the exhaust or the spark plug tips are black from excess fuel burning carbon. But that just doesn't explain why the car stuttered and died down at partial throttle. So I'm assume it's not all the wideband's faulty readings.

 

[vettesmoker]

just a thought, if you have any ignition misfire, you will smell the unburnt fuel, but the wideband will pick up the unburnt oxygen and give a leaner reading. if you havent figured it out yet, change those plugs, check your fuel trims, and 02 activity. post a log if you got it.