Wierd CEL CODE!
12-11-2002, 04:18 AM
#1
Senior Member
Thread Starter
Join Date: Feb 2002
Posts: 463
Likes: 0
Received 0 Likes
on
0 Posts
Wierd CEL CODE!
Hey yall, yesterday morning on my way to work my CEL came on again. 2 months earlier i had replaced the first O2 sensor. I was getting a "catalyst below minimum threshold" cel (i installed a new high flow cat w/ 2.25 system prior to this CEL about 4 months ago). It didn't say bank 1 O2 bad or anything but i suspected it to be a little wacky working with a new cat(107k miles on the O2 sensor at the time). So i replaced the O2 sensor. No more CEL until yesterday morning. It came on at around 107,950 miles. Well, i got it scanned at a local autozone and the code read like below.
DTC
P1123
I was told it's one of four dealer specific codes. I'm about to call up my neighborhood *hopefully* friendly Hyundai dealer and see if they give me a legitimate answer but i wanted to run this by you all and see if anyone had a "truthfull" answer. Autozone said it was probably a predetermined CEL to come on at a certain milage so i can let my dealer rape my wallet. What do you guys think???
[ December 11, 2002, 12:36 PM: Message edited by: Koreandude ]
DTC
P1123
I was told it's one of four dealer specific codes. I'm about to call up my neighborhood *hopefully* friendly Hyundai dealer and see if they give me a legitimate answer but i wanted to run this by you all and see if anyone had a "truthfull" answer. Autozone said it was probably a predetermined CEL to come on at a certain milage so i can let my dealer rape my wallet. What do you guys think???
[ December 11, 2002, 12:36 PM: Message edited by: Koreandude ]
12-11-2002, 04:27 AM
#2
Senior Member
Join Date: May 2001
Posts: 1,547
Likes: 0
Received 0 Likes
on
0 Posts
Vehicle: Ex Hyundai Owner
you can go into www.hmaservice.com and in the WEBTECH, go to SEARCH and enter the specific code:
this one says and it explains why you may have needed a new CAT:
[ December 11, 2002, 11:28 AM: Message edited by: Bat Lord ]
this one says and it explains why you may have needed a new CAT:
QUOTE
DTC - P1123 (FUEL TRIM ADDITIVE AIR SYSTEM TOO RICH) Â
PRIMARY COMPONENTS: Air/Fuel Control System
SECONDARY SENSOR(S): Mass Air Flow (MAF) Sensor, Throttle Position (TP) Sensor, Intake Air Temperature (IAT) Sensor, Engine Coolant Temperature (ECT) Sensor, Oxygen Sensors
SYSTEM(S): Bosch
NORMAL PARAMETERS: Not applicable
CIRCUIT DESCRIPTION
The air/fuel control system, in addition to a number of sensors, includes the following components and systems:
Intake air system.
Exhaust system.
Evaporative emissions control system (includes purge control solenoid valve).
Fuel injectors.
Fuel pressure regulator.
Fuel pump.
For the air/fuel ratio to be within limits, all of the sensors, components and systems associated with the air/fuel control system must function within normal parameters.
FAILURE CONDITIONS
Accent (DOHC)
The ECM will set a code and the Malfunction Indicator Lamp (MIL) will turn on if the short-term fuel trim additive value is less than 0.4 milliseconds, or 10% to 15% rich for 30 seconds during two back-to-back trips when the following conditions are met:
ECM is in closed loop operation.
Engine speed is below 1000 RPM.
Engine coolant temperature is above 158°F (70°C).
Canister purge system is not operating.
Mass air flow is less than 5.5 g/s.
Accent (SOHC) and Elantra
The ECM will set a code and the Malfunction Indicator Lamp (MIL) will turn on if the short-term fuel trim value goes 10% to 15% rich for 30 seconds during two back-to-back trips when the following conditions are met:
ECM is in closed loop operation.
Engine speed is below 1000 RPM.
Engine coolant temperature is above 158°F (70°C).
Canister purge system is not operating.
Mass air flow is less than 7.5 g/s (Accent) or 6.6 g/s (Elantra).
NOTE
Engine load is determined by first dividing air flow per crankshaft revolution by the mass air flow sensor hot film constant (constant is based on the number of fuel injectors and injector's mass flow constant). This value is then adjusted by using engine speed and throttle position readings.
PRIMARY COMPONENTS: Air/Fuel Control System
SECONDARY SENSOR(S): Mass Air Flow (MAF) Sensor, Throttle Position (TP) Sensor, Intake Air Temperature (IAT) Sensor, Engine Coolant Temperature (ECT) Sensor, Oxygen Sensors
SYSTEM(S): Bosch
NORMAL PARAMETERS: Not applicable
CIRCUIT DESCRIPTION
The air/fuel control system, in addition to a number of sensors, includes the following components and systems:
Intake air system.
Exhaust system.
Evaporative emissions control system (includes purge control solenoid valve).
Fuel injectors.
Fuel pressure regulator.
Fuel pump.
For the air/fuel ratio to be within limits, all of the sensors, components and systems associated with the air/fuel control system must function within normal parameters.
FAILURE CONDITIONS
Accent (DOHC)
The ECM will set a code and the Malfunction Indicator Lamp (MIL) will turn on if the short-term fuel trim additive value is less than 0.4 milliseconds, or 10% to 15% rich for 30 seconds during two back-to-back trips when the following conditions are met:
ECM is in closed loop operation.
Engine speed is below 1000 RPM.
Engine coolant temperature is above 158°F (70°C).
Canister purge system is not operating.
Mass air flow is less than 5.5 g/s.
Accent (SOHC) and Elantra
The ECM will set a code and the Malfunction Indicator Lamp (MIL) will turn on if the short-term fuel trim value goes 10% to 15% rich for 30 seconds during two back-to-back trips when the following conditions are met:
ECM is in closed loop operation.
Engine speed is below 1000 RPM.
Engine coolant temperature is above 158°F (70°C).
Canister purge system is not operating.
Mass air flow is less than 7.5 g/s (Accent) or 6.6 g/s (Elantra).
NOTE
Engine load is determined by first dividing air flow per crankshaft revolution by the mass air flow sensor hot film constant (constant is based on the number of fuel injectors and injector's mass flow constant). This value is then adjusted by using engine speed and throttle position readings.
[ December 11, 2002, 11:28 AM: Message edited by: Bat Lord ]
12-11-2002, 05:27 AM
#3
Senior Member
Thread Starter
Join Date: Feb 2002
Posts: 463
Likes: 0
Received 0 Likes
on
0 Posts
QUOTE
Bat Lord:
this one says and it explains why you may have needed a new CAT:
Well, i didn't get the the first CEL until AFTER i bought a new exhaust system including the Carsound cat. If this new CEL that occurd yesterday, the P1123 code, is suggesting my cat is bad, then wtf??? It's got less than 6k miles on it!! Your reply Batlord of what is listed under WebTech mentioned pretty much every sensor i could think of. And i took it that any of these sensors could trigger this code, but why this code if the sensor is failing?? I thought the whole point of a OBDII system was to help pinpoint the problematic sensor w/ sensor specific codes. So what is this P1123 stuff? Was i running lean/rich for that time and if i was why/how? Damn car is falling apart.. this one says and it explains why you may have needed a new CAT:
btw, it didn't come on this morning...so far. It just seems to me that this code is too generic. Forgive me, but I'm not quite sure what it's saying. 
[ December 11, 2002, 12:34 PM: Message edited by: Koreandude ]
12-12-2002, 05:01 PM
#4
Super Moderator
Join Date: May 2001
Location: Rancho Palos Verdes, CA
Posts: 11,851
Likes: 0
Received 2 Likes
on
2 Posts
Vehicle: 2008 Toyota Prius 2006 Suzuki SV650S
Moving to HELP forum.
You've either got excess fuel pressure, or your not getting enough air at idle.
Try opening up the idle adjustment screw on the TB 2 turns.
QUOTE
The ECM will set a code and the Malfunction Indicator Lamp (MIL) will turn on if the short-term fuel trim additive value is less than 0.4 milliseconds, or 10% to 15% rich for 30 seconds during two back-to-back trips when the following conditions are met:
ECM is in closed loop operation.
Engine speed is below 1000 RPM.
Engine coolant temperature is above 158°F (70°C).
Canister purge system is not operating.
Mass air flow is less than 5.5 g/s.
It's saying you are too rich at idle, not that the cat is bad.ECM is in closed loop operation.
Engine speed is below 1000 RPM.
Engine coolant temperature is above 158°F (70°C).
Canister purge system is not operating.
Mass air flow is less than 5.5 g/s.
You've either got excess fuel pressure, or your not getting enough air at idle.
Try opening up the idle adjustment screw on the TB 2 turns.
12-12-2002, 10:49 PM
#5
Senior Member
Join Date: Feb 2002
Location: apex. nc
Posts: 197
Likes: 0
Received 0 Likes
on
0 Posts
Vehicle: 2005 tiburon gt
QUOTE
I thought the whole point of a OBDII system was to help pinpoint the problematic sensor w/ sensor specific codes.
from working at a dealer i can give you a little more insight on this. obdII does pinpoint it down alot, but not always totally. to get the exact code and exact sensor you need to go to the dealer where they have a much more sophisticated computer that tests all these sensors while still in the car one by one and than from there tells you which one is bad and needs to be replaced.