KOEO & continuous memory codes??

12-15-2003, 03:25 PM

Hey guys. Well I figured I'd do the self test and see what codes my car was spitting out. My check engine light on my '90 GT has been flashing since I rebuilt my motor years ago. When I did the rebuild I ripped all the smog stuff out (pump, charcoal canister, & all the plumbing) and plugged the back of the heads. My stang doesn't have cats either. That said...the KOEO code I pulled was 85. The continuous memory codes that I pulled were 41 & 91...which are both the same. It's strange though...because my Chiltons manual shows all three of these codes as having several listings, for the same code?? Why is that?
PKRWUD...are you still out there?? Or anyone else who can help me out...any ideas on how I can get these codes wiped out? I know you can clear the continuous memory codes by disconnecting the jumper wire during the test. But I want to know why these codes are popping up? Here is what the Chiltons manual reads:

85 - Canister purge circuit failure
85 - Canister purge solenoid circuit failure
85 - Adaptive fuel lean limit reached

41 - HEGO sensor circuit indicates system lean
41 - No HEGO switching detected

91 - HEGO sensor idicates system lean
91 - No HEGO switching detected

Since the term "lean" is mentioned in all three codes, I pulled a plug and it looked perfect as usual. I run around 39psi. with the vacuum line attached to the FPR. My fuel system consists of 24lb. injectors...155lph intank pump...200gph inline pump-for nitrous). Do you think all of these codes are linked to the removal of the smog equipment? I assume the term "canister" in code-85 is referring to the purge circuit/solenoid in the charcoal canister. My charcoal canister is no longer in my car...so I guess that explains that one? Codes 41 & 91 both mention HEGO. I know HEGO stands for Heated Exhaust Gas Oxygen, but I really don't know what this sensor/circuit does or reads exactly?? It's not the oxygen sensors...those are fairly new. I plan on doing a KOER test in the next couple of days. In the mean time...can anyone shed some light on this for me?
Also...does having your check engine light flash occasionally mean that my car is running in "open loop" mode? Isn't that sort like a limp mode...with a safe set air/fuel ratio of some sort? What I'm getting at is...is my car running to it's full potential being that my check engine light does still flash? Sorry this is so long. Thanks in advance.

Simi-

12-15-2003, 06:05 PM

Wow...so no one has a clue, huh? Darn it. Any EEC-IV pros out there??? Anyone??

canukracer · 12-16-2003, 12:35 AM

the hego's are the oxygen sensors, these on your car are heated so they get up to temp faster to go into closed loop, just cause they are new don't mean they are good, they don't separate left from right so it could only be one of the two that is causing the code or lean reading

12-16-2003, 12:41 PM

Oh...I feel dumb now. Never knew that the HEGO was the O2 sensor?? Thanks man...I'll check them out.

12-16-2003, 02:37 PM

What about my fuel pressure? Do you think 38-39psi. with the vacuum line attached to the FPR is about right? Anyone??

12-15-2003, 03:25 PM	#1
Simi Stang Guest Posts: n/a	KOEO & continuous memory codes?? Hey guys. Well I figured I'd do the self test and see what codes my car was spitting out. My check engine light on my '90 GT has been flashing since I rebuilt my motor years ago. When I did the rebuild I ripped all the smog stuff out (pump, charcoal canister, & all the plumbing) and plugged the back of the heads. My stang doesn't have cats either. That said...the KOEO code I pulled was 85. The continuous memory codes that I pulled were 41 & 91...which are both the same. It's strange though...because my Chiltons manual shows all three of these codes as having several listings, for the same code?? Why is that? PKRWUD...are you still out there?? Or anyone else who can help me out...any ideas on how I can get these codes wiped out? I know you can clear the continuous memory codes by disconnecting the jumper wire during the test. But I want to know why these codes are popping up? Here is what the Chiltons manual reads: 85 - Canister purge circuit failure 85 - Canister purge solenoid circuit failure 85 - Adaptive fuel lean limit reached 41 - HEGO sensor circuit indicates system lean 41 - No HEGO switching detected 91 - HEGO sensor idicates system lean 91 - No HEGO switching detected Since the term "lean" is mentioned in all three codes, I pulled a plug and it looked perfect as usual. I run around 39psi. with the vacuum line attached to the FPR. My fuel system consists of 24lb. injectors...155lph intank pump...200gph inline pump-for nitrous). Do you think all of these codes are linked to the removal of the smog equipment? I assume the term "canister" in code-85 is referring to the purge circuit/solenoid in the charcoal canister. My charcoal canister is no longer in my car...so I guess that explains that one? Codes 41 & 91 both mention HEGO. I know HEGO stands for Heated Exhaust Gas Oxygen, but I really don't know what this sensor/circuit does or reads exactly?? It's not the oxygen sensors...those are fairly new. I plan on doing a KOER test in the next couple of days. In the mean time...can anyone shed some light on this for me? Also...does having your check engine light flash occasionally mean that my car is running in "open loop" mode? Isn't that sort like a limp mode...with a safe set air/fuel ratio of some sort? What I'm getting at is...is my car running to it's full potential being that my check engine light does still flash? Sorry this is so long. Thanks in advance. Simi- Last edited by Simi Stang; 12-15-2003 at 05:41 PM..

12-15-2003, 06:05 PM	#2
Simi Stang Guest Posts: n/a	hello?? Wow...so no one has a clue, huh? Darn it. Any EEC-IV pros out there??? Anyone??

12-16-2003, 12:41 PM	#4
Simi Stang Guest Posts: n/a	thanks Oh...I feel dumb now. Never knew that the HEGO was the O2 sensor?? Thanks man...I'll check them out.

12-16-2003, 02:37 PM	#5
Simi Stang Guest Posts: n/a	fuel psi. What about my fuel pressure? Do you think 38-39psi. with the vacuum line attached to the FPR is about right? Anyone??

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12-16-2003, 12:35 AM	#3
canukracer Registered Member Join Date: Jul 2003 Location: alberta canada Posts: 108	the hego's are the oxygen sensors, these on your car are heated so they get up to temp faster to go into closed loop, just cause they are new don't mean they are good, they don't separate left from right so it could only be one of the two that is causing the code or lean reading