Ok, a little background first. The car has a ATI Procharger w/ 7psi pulley, 255lph fuel pump, 550cc injectors, 2 step colder NGK spark plugs, headers, stock cats, Magnaflow cat back. For tuning I have a UTEC with the MAP sensor.

Before I installed the injectors I was running rather lean, then once the injectors were in it was rich as hell. I tweaked the maps until it was as good as I could get it. The AFR gauge was reading normal, 14.5 during cruising and 12 and under while under load. This afternoon the AFR went up to 20 and has stayed there! It was all of the sudden. No indicators or anything!

I looked to see if the plug covering an additional O2 sensor bong was missing, but it is there. The sensor itself is not that old and has only been in the car about a month or so. So I do not think it's it. The car does feel different but no to the point that is soooooo lean! I remember reading that there is a way of connecting the WB O2 to the UTEC, but have not found it on the manual.

Anyways, does anyone have any suggestions as to what might be happening here? Thanks!

 

your car wouldnt even run if the AFR was 20. 20 means the injectors are off.
your sensor could be dead.

you cannot connect the wideband directly to the UTEC. It can only be joined thru software in the logs.

 

Lol@bong. Did you bottom out, maybe damaged the sensor? Sounds like a bad sensor. Make sure all connections are tight, etc.

 

what wideband are you using? some widebands need recalibration every now and then

 

It's an AEM UEGO... The sensor was sitting for about a year before installation... I don't know if it's my mind playing tricks on me, but the car feels different! Will have to order another sensor to see if that is the case! FML...

 

it sure would feel different if the AFR was really 20, as in the car would come to a complete stop.

 

Well at least you guys are putting me at ease. Another friend told me that he had the same issue and it was the OEM O2 sensors that went bad... I will try replacing them tonight to see if that does it!

 

This is crazy... But the car threw a CEL of 0172... Rich on bank one! So it must be the WB O2 for the gauge that is acting up!