Help!!! How to check for bad O2 Sensor?
Thread Starter
Race Director
Joined: May 2003
Posts: 19,105
Likes: 2
From: Paducah KY
Cruise-In VII Veteran
Help!!! How to check for bad O2 Sensor?
Does anybody know how to check for a bad 02 Sensor?
Car is missing/cutting out real bad and smoking out exhaust. It won't hardly even idle on its own until eng. temp. reaches about 150 degrees. Its like its only running on one bank of cylinders. I've checked all fuses O.K. in engine compt. & passenger floor board.
Throws this code everytime it's started: P1133
(Heated Oxygen Sensor)
This started after having ATI Blower & Headers installed. Cats were removed and I'm running straight back to stock exhaust. Rear 02 Sensors were relocated up front on headers.
Car ran great the first couple hrs. after the install then started missing bad.
The next day it started running good for about another hr. then it started cutting out real bad again and has been that way for a week now.
To make things worse there's no performance shops here local that deal with these problems. Is there any way I can check the 02 Sensors myself to see if one is bad?
Also if anyone knows a good shop or mechanic in my surrounding area please let me know. I'm located in Western KY., about 3 hrs. drive either way to Memphis, TN or St. Louis, MO.
2hrs. north of Nashville, TN
Thanks, any help would be greatly appreciated.
Jim :confused: :eek: :confused: :eek:
Car is missing/cutting out real bad and smoking out exhaust. It won't hardly even idle on its own until eng. temp. reaches about 150 degrees. Its like its only running on one bank of cylinders. I've checked all fuses O.K. in engine compt. & passenger floor board.
Throws this code everytime it's started: P1133
(Heated Oxygen Sensor)
This started after having ATI Blower & Headers installed. Cats were removed and I'm running straight back to stock exhaust. Rear 02 Sensors were relocated up front on headers.
Car ran great the first couple hrs. after the install then started missing bad.
The next day it started running good for about another hr. then it started cutting out real bad again and has been that way for a week now.
To make things worse there's no performance shops here local that deal with these problems. Is there any way I can check the 02 Sensors myself to see if one is bad?
Also if anyone knows a good shop or mechanic in my surrounding area please let me know. I'm located in Western KY., about 3 hrs. drive either way to Memphis, TN or St. Louis, MO.
2hrs. north of Nashville, TN
Thanks, any help would be greatly appreciated.
Jim :confused: :eek: :confused: :eek:
Burning Brakes
Joined: Feb 2002
Posts: 1,137
Likes: 2
From: Texas
Re: Help!!! How to check for bad O2 Sensor? (Z06-JIM)
Do you have AutoTap or EFI Live? If you do you can log the O2 sensor voltage versus time. When mine went out, the voltage amplitude swing was very low. P1133 is bank 1 sensor 1 which is the front drivers side. Both of my front sensors went out at different times after I got the ATI and headers, but I did not experience the symptoms you describe. I just got the codes, otherwise the car ran fine.
Check to make sure that you do not have a boost leak anywhere in the plumbing.
Check to make sure that you do not have a boost leak anywhere in the plumbing.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Re: Help!!! How to check for bad O2 Sensor? (R6_C5_ML430)
Jim
I check my O2 sensors by using a digital volt meter. Put the neg lead to ground and the pos wire on the signal lead of the sensor. You will see any where from 200 milivolts to 900 milivolts. When the engine is idling you should see the voltage go low 200-400 mv for a short time and then swing high 500-900 mv. It will / should swing back and forth while it is idling. The toggle is the computer sensing the voltage abd adjusting the air fuel ratio. If the computer adds or substracts fuel to adjust the air fuel ratio and the voltage output of the O2 sensor stays the same i.e. 500mv then the computer trips the error code. The O2 sensor acts like a battery when exposed to high heat and oxygen. The lack of oxygen (RICH) causes the sensor to go low voltage and the extra oxygen (LEAN) causes it to go high.
If you blip the throttle you should see it go low as the injectors squirt fuel to rev the engine and then high as the she winds down during the injector shut off period.
If your Sensor voltages just sits at one voltage, the O2 sensor is BAD!
Bill Curlee
[Modified by Bill Curlee, 4:15 PM 7/26/2003]
[Modified by Bill Curlee, 4:18 PM 7/26/2003]
I check my O2 sensors by using a digital volt meter. Put the neg lead to ground and the pos wire on the signal lead of the sensor. You will see any where from 200 milivolts to 900 milivolts. When the engine is idling you should see the voltage go low 200-400 mv for a short time and then swing high 500-900 mv. It will / should swing back and forth while it is idling. The toggle is the computer sensing the voltage abd adjusting the air fuel ratio. If the computer adds or substracts fuel to adjust the air fuel ratio and the voltage output of the O2 sensor stays the same i.e. 500mv then the computer trips the error code. The O2 sensor acts like a battery when exposed to high heat and oxygen. The lack of oxygen (RICH) causes the sensor to go low voltage and the extra oxygen (LEAN) causes it to go high.
If you blip the throttle you should see it go low as the injectors squirt fuel to rev the engine and then high as the she winds down during the injector shut off period.
If your Sensor voltages just sits at one voltage, the O2 sensor is BAD!
Bill Curlee
[Modified by Bill Curlee, 4:15 PM 7/26/2003]
[Modified by Bill Curlee, 4:18 PM 7/26/2003]
Burning Brakes
Joined: Feb 2002
Posts: 1,137
Likes: 2
From: Texas
Re: Help!!! How to check for bad O2 Sensor? (Z06-JIM)
I would also add that when you pull the O2 sensors out, it they are very orange, you could have a blown head gasket (coolant will cause them to turn orange). If you have been using octane booster, they will be a little orange from that, so don't freak out if you have been using booster and they are orangish.
--Sean
--Sean
