car idleing very lean

[v8killer]

well the car has the following that may help you figure out what causeing my lean idle condition. i have a AEM wb and it goes full lean ---- after startup. i have the 2g mas side screens out could that be causing it to go full lean ! i do have a very slight exhaust leak at the downpipe. parts ar in my profile. Thanks !

 

[JayRolla]

Do you have fuel control?? Is cruising still around 14.7 and WOT under 11.1?? I think a lot of stock dsm's run lean at idle, thats why we have to add a lot at idle to get a good afr. But since you are not under load at all, you should be fine. Wouldnt hurt to add fuel at that rpm and get a better afr if you have fuel control.

 

[v8killer]

yes i have a moates ostrich and tunerpro rt so i can go up in that area i just didn't think it should be that lean, i may try and put the screensback in and see if that makes it richer .

 

[anteversion]

A little exhaust leak before the WB o2 sensor is causing that situation. Exhaust gases, when flowing trough the exhaust pipe are creating a vaccuum wich is sucking fresh air into the exhaust pipe. Then, your o2 sensor is fooled by this fresh air.... and believe me, it wont take that much of a leak to completely fool o2 reading

 

[1992awdlaser]

A little exhaust leak before the WB o2 sensor is causing that situation. Exhaust gases, when flowing trough the exhaust pipe are creating a vaccuum wich is sucking fresh air into the exhaust pipe. Then, your o2 sensor is fooled by this fresh air.... and believe me, it wont take that much of a leak to completely fool o2 reading

Exactly right.

 

[JayRolla]

A little exhaust leak before the WB o2 sensor is causing that situation. Exhaust gases, when flowing trough the exhaust pipe are creating a vaccuum wich is sucking fresh air into the exhaust pipe. Then, your o2 sensor is fooled by this fresh air.... and believe me, it wont take that much of a leak to completely fool o2 reading

Good answer right there. I was thinking of that. It has to be his issue if he cant get a good afr at idle.

 

[v8killer]

thanks guys i will try all you guys advice. starting with the mas screens "glad i kept them" then the exhaust leak.