OBD2 Fuel System Status Diagnosis - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Nutbutt · 01-03-2014, 08:42 AM

Noticed that after about a 30 min drive my OBD2 Fuel System Status on bank 1 & 2 go from "close loop using HO2S" to "close loop faulty HO2S". No codes or CEL being set.
I have been told that one of my upper O2 sensors may be reacting slowly or failing. Or a lower may be failing. Or one of the cats may be failing ?
No real noticeable difference in idle once the status changes.
Any thoughts ?

Nutbutt · 03-24-2014, 06:46 PM

Well replaced the upper O2s and no effect on the fuel system status.
From some research it could be the lower O2s also.
Any other suggestions ?

DSX_Camaro · 04-23-2014, 12:05 PM

Did you check your cats yet? (Lower O2s are only for emissions btw)

Nutbutt · 04-23-2014, 01:20 PM

Yep, checked the cats, they were fine. Seem that fuel system status, CL faulty HO2S doesn't effect emissions since all my readiness flags are set.
I still can't find anyone who knows what this actually means in terms of possible component failures.

01-03-2014, 08:42 AM	#1
Nutbutt Drives: 2011 RJT 2LT/RS Convertible Join Date: Nov 2009 Location: Western Massachusetts Posts: 3,381 View My Garage	OBD2 Fuel System Status Diagnosis Noticed that after about a 30 min drive my OBD2 Fuel System Status on bank 1 & 2 go from "close loop using HO2S" to "close loop faulty HO2S". No codes or CEL being set. I have been told that one of my upper O2 sensors may be reacting slowly or failing. Or a lower may be failing. Or one of the cats may be failing ? No real noticeable difference in idle once the status changes. Any thoughts ? __________________ 1st IPF Supercharged 2011 2LT/RS RJT Convertible

03-24-2014, 06:46 PM	#2
Nutbutt Drives: 2011 RJT 2LT/RS Convertible Join Date: Nov 2009 Location: Western Massachusetts Posts: 3,381 View My Garage	Well replaced the upper O2s and no effect on the fuel system status. From some research it could be the lower O2s also. Any other suggestions ? __________________ 1st IPF Supercharged 2011 2LT/RS RJT Convertible

04-23-2014, 12:05 PM	#3
DSX_Camaro Drives: 2013 SW 2LT/RS LFX/AY6 Join Date: Feb 2013 Location: Orlando, FL Posts: 1,741	Did you check your cats yet? (Lower O2s are only for emissions btw) __________________ K&N CAI, 1LE Strut Tower Brace, Elite Engineering Catch Can and Clean Side Separator, Apex Scoop w/ Washer Relocation Kit, CTS Front Calipers and Rotors, JacFab Ported Intake Manifold, JacFab Intake Manifold Spacer, 80mm Overkill Throttle Body, SS Brake Lines, Ideal Garage Master Cylinder, Monster Twin Disc Clutch, NPP Retrofit w/ Magnaflow Resonated X, ARH Catless Downpipes, JRE Built 3.45 Diff, 1LE Axles, 1LE Hubs, Overkill Tuned, BMR Anti Wheel-hop Kit Stage I, ACS TL1 Hood Insert, ZL1 Spoiler

04-23-2014, 01:20 PM	#4
Nutbutt Drives: 2011 RJT 2LT/RS Convertible Join Date: Nov 2009 Location: Western Massachusetts Posts: 3,381 View My Garage	Yep, checked the cats, they were fine. Seem that fuel system status, CL faulty HO2S doesn't effect emissions since all my readiness flags are set. I still can't find anyone who knows what this actually means in terms of possible component failures. __________________ 1st IPF Supercharged 2011 2LT/RS RJT Convertible