My car is basically stock. Has a test pipe and that is it. I installed a wideband and boost gauge about two weeks ago. The past few days I noticed the wideband at idle was reading 16.4-16.7 and around 12.2 under load rather than the normal 14.2 at an idle. The boost gauge is still reading between 18-21 for vacuum and the boost gauge still reflects the same boost as before.
The o2 sensor is in the test pipe so wouldn't it be an exhaust leak between there and the downpipe?

 

ur running lean, check to see if the hose came off your fuel pressure regulator. If it did ziptie it down

 

Its still there.

 

If your car is operating in closed loop while WB is reading 16:1, it's more likely as you stated an exhaust leak between WBO2 sensor and head. If you tighten everything and know for certain there is no leaking and it continues, buy another O2 sensor. And also what the firefighter said below

People are very quick to add their 2 cents worth, whether worth 2 cents or not, you may also suggest checking wires in the ecu harness for chaffing.
Even better, face the car's tail pipe while idling and lay on the driveway at plank position for 4 minutes. You should not care about a 16:1 AFR at that time anymore.


BTW, how long can everyone do plank out there, I'm getting close to 6 minutes

 

Did you check the calibration on the wideband?

 

Lol. I'm really thinking its in the exhaust. I'm going to order 3inch downpipe and catback to match the testpipe. That half inch would probably be hard to line up perfectly. Its weird to me how it would just now start though out of nowhere.

No. Didnt know widebands had to be calibrated.

 

I've owned more than one and they did indeed need to be calibrated before install and periodically after. What kind do you have?

 

Prosport.

 

http://prosportgauges.com/Wideband%2...structions.pdf

See page #3 item #1 you should remove the O2 sensor from the exhaust pipe and do this in fresh air.

 

Thank you sir. Haven't driven her this week. Doing a full exhaust Saturday and will do this as well.

 

You can do it without pulling the sensor also, just run the car up to about 40 MPH or so in 3rd gear turn the key off and coast for at least 10 seconds or so with the throttle wide open, this will pump any exhaust and or unburned fuel out of the exhaust system. Clutch in and coast to the side of the road and it's time to calibrate, turn the key back on and follow the calibration procedures for you particular model of wideband.

PS Don't try this in rush hour traffic on the 405!!