TripleWhite96

iTrader: (29)

I don't understand this thing, since I got it the thing shoots back and forth constantly making a lightshow in my car. On the dyno the car is constant 11.5-11.6, doesn't move its great...I put the AEM sensor back in and take it for a stroll, start up it will go stupid lean then after itll warm up read perfect at idle(sometimes) other times it will be like OMG 15.6 then shoot down to _.__. I checked for exhaust leaks didn't hear anything. I have a cutout and i'm wondering if the position where its at is causing an issue, but closed or open the thing still is a mess.

Here is a picture of the cutout and its location, its now electronic and at the time the sensor bung was just sealed with an old O2 in the picture. 3in downpipe from turbo about 2 feet into the wideband then the cutout.

sujomatt

iTrader: (7)

that happened on my STi when the bosch sensor's wiring melted on the transmission leading up to the interior of the car lol

mike13

iTrader: (27)

when cruising does it stay around 14.7-15.1? Your computer is continually adjusting the A/F going from slightly lean to slightly rich, don't be concerned with the lean start up it's my understanding that it's the wideband warming up.

All that bouncing around is actually what's going on with your fuel mixture, when idling or cruising your pcm is making all those adjustments. Same with coasting the mixture gets goofy especially if it's been tuned. If it stays between 14.7-15.1 when cruising and richens up when under hard acceleration I think it's working correctly.

12secSS

iTrader: (30)

That sounds absolutely normal. I see you have no cats, but if you left the air pump on in the tune, then the AFR will read lean on start up. The air pump flows cool fresh air to the cats to help run them lean to warm them up quicker. As for driving around, if you are tuned in closed loop the ECM will bounce around the AFR from lean to rich. This is the only way the ECM can determine if the AFR is at the desired level. The ECM tries to swing around 500mV on the narrow bands. Also when you are decelerating, the ECM will kick into DFCO (Deceleration Fuel Cut Off) mode, and this can look super lean to a wideband, but it helps fuel economy and doesn't hurt the engine as spark is reduce to zero as well under this condition.

OUTLAWZ RACING

iTrader: (9)

You just solved my buddy problem. Hell I never though about that stupid air pump. Thanks Oh not the op tho.

mike13

iTrader: (27)

Me neither, I always thought it was the heater circuit in the wide band. So does the air pump stay on until it goes closed loop? Also is that the only purpose of the air pump?

TripleWhite96

iTrader: (29)

The airpump is out and holes are plugged, I'll check with my tuner tomorrow to see if its off in the tune..the thing freaks me out because as i'm driving its never balanced lol. I know about DFCO, my wideband reads around 10-11.5 during that, so I don't know what the deal is..on the computer though it reads 11.5-11.6 consistent the entire time.

Haans249

iTrader: (24)

You're not reading DFCO if your AFR is 10-11.5. DFCO is "Direct Fuel Cut-Off" and when you hit it, you should be reading 19 AFR. It sounds to me like your tune needs work. I doubt its the wideband if its wired properly and not damaged. If your VE table is not set properly, you can have LARGE swings in AFR, so the other people who are telling you its normal under a wideband are dead wrong. At idle you should be reading 14.63, at cruising through the rpm's at low throttle and low rpms (3000 and below and 20% and less throttle) you should be reading 14.63 constantly. Once you start getting into your powerband then the AFR should transition smoothly to 12.5:1 for your turbo app.

Its not the wideband, ITS THE TUNE.

sujomatt

iTrader: (7)

yea when i was saying it may be damaged - it would be stuck at some AFR in the 15's and randomly go back to reading. it was really weird. good luck figuring it out man

The Fugitive

iTrader: (6)

what setting do you have your wideband set at P0, P1, P2 etc?