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Spooner
08-11-2006, 01:02 PM
My check engine light came on in my 97 blazer 4.3L. I scanned it on a obd2 scanner and I get a P0134 code (o2 Sensor Curcuit No Activity Detected Bank 1 Sensor 1) It seems to be running rich as well. Most likely from the code. Any ideas besides BURN IT?

StinkFinger
08-11-2006, 01:04 PM
repace the o2 sensor

Big_Ern
08-11-2006, 01:13 PM
its a chevy, burn it[f]



seriously tho, Stinky is right... the computer is telling you whats wrong, so fix it:rolleyes:

its running rich because the o2 sensor isn't working.

but before you replace anything, check that it didn't just come uplugged or wire melted etc

Pudge
08-11-2006, 01:14 PM
pull the motor, I think it is shot, put in a rebuild, and I'll come grab your old scrap one.

Spooner
08-11-2006, 02:01 PM
pull the motor, I think it is shot, put in a rebuild, and I'll come grab your old scrap one.


Yourr a funny guy I just replaced the engine last summer. I did replace the the o2 sensor just before the cat. I was told by Builtauto that was the one that needed to be changed. I did that after the reset of the computer it set the code agian.

Big_Ern
08-11-2006, 02:02 PM
check the wiring for it

Pudge
08-11-2006, 02:18 PM
Yourr a funny guy I just replaced the engine last summer. I did replace the the o2 sensor just before the cat. I was told by Builtauto that was the one that needed to be changed. I did that after the reset of the computer it set the code agian.



sounds like the motor is done again due to the fact your o2 sensor wrecked it. I'll need a few days to line up truck to grab your scrap[15]

good luck dude[cheers]

Spooner
08-11-2006, 02:56 PM
[15] [15] [15] [15] [15] [15]

StinkFinger
08-11-2006, 02:57 PM
doyou have another o2 on it perhaps on the manifold

Spooner
08-11-2006, 05:33 PM
3 more 4 in all so I guess I change them out too. I took a look at the wires and conection and all is good. So the other 3 sensors must be shot too.

Pudge
08-11-2006, 07:20 PM
na, motors done

duff
08-11-2006, 09:11 PM
bank 1 sensor 1 is the drivers front, also a vacume leak can cause the 02 to have low acticity

Spooner
08-12-2006, 03:43 PM
Never thought about a vaccum leak. Cool thanks for the help

Crashmaster
08-12-2006, 07:35 PM
Since the code returns right away I'ld bet on an open circuit. A vacuum leak or cracked manifold would set a mixture control limit code. O2s don't tend to get stuck in the middle of their range mostly high, or low. P0134 is when the circuit is open and the computer only reads the 0.45V reference signal it sends out the high side of the circuit. This is what I would look for, if you don't have 0.45V (less depending on some cheap meters) at the purple/white wire in the b1s1 connector, the high side circuit is open. The low side (prob light brown) should light a test light connected to Batt+.

The richness is due to the computer not entering closed loop because of the code present. Open loop is always biased rich.

Spooner
08-12-2006, 09:23 PM
Since the code returns right away I'ld bet on an open circuit. A vacuum leak or cracked manifold would set a mixture control limit code. O2s don't tend to get stuck in the middle of their range mostly high, or low. P0134 is when the circuit is open and the computer only reads the 0.45V reference signal it sends out the high side of the circuit. This is what I would look for, if you don't have 0.45V (less depending on some cheap meters) at the purple/white wire in the b1s1 connector, the high side circuit is open. The low side (prob light brown) should light a test light connected to Batt+.

The richness is due to the computer not entering closed loop because of the code present. Open loop is always biased rich.

I have limited skills in auto repair. I am just trying to learn as I go so I apologize for the stupid questions. So I check the volts at the connector with a muti meter? If it shows that the high side circuit is open does that mean the sensor is shot and needs to be replaced?

Crashmaster
08-13-2006, 10:56 AM
No problem. I ashoom the sensor is fine since it was replaced. A new sensor couldn't fail fast enough to trigger the code right away anyways.

Of the four wires to the B1S1 O2 the purple/white and tan/white are the possible problems.

Two ways to check this are to measure the continutity from one end to the other of each wire. This requires the computer to be unplugged, right pins found and long jumper wires. Easier is to check the wires from the connector. With the key on and the O2 unplugged. The low side (tan/white) is a near perfect ground through the computer, easy to check with a (high resistance)test light. The purple/white is the O2 signal (higher voltage side), the computer sends 0.45V up this wire through a huge resistance to diagnose this very code.

So with key on, sensor unplugged, ground at tan wire and a very weak 0.45V at the purple wire would tell you the wiring is fine. If not, the open is between the O2 connector and computer somewhere -> replace wires.

It is possible there is a failure internal to the computer, but naw, not likely. I'ld bet on wireing damaged during the motor swap.

Spooner
08-14-2006, 02:45 AM
No problem. I ashoom the sensor is fine since it was replaced. A new sensor couldn't fail fast enough to trigger the code right away anyways.

Of the four wires to the B1S1 O2 the purple/white and tan/white are the possible problems.

Two ways to check this are to measure the continutity from one end to the other of each wire. This requires the computer to be unplugged, right pins found and long jumper wires. Easier is to check the wires from the connector. With the key on and the O2 unplugged. The low side (tan/white) is a near perfect ground through the computer, easy to check with a (high resistance)test light. The purple/white is the O2 signal (higher voltage side), the computer sends 0.45V up this wire through a huge resistance to diagnose this very code.

So with key on, sensor unplugged, ground at tan wire and a very weak 0.45V at the purple wire would tell you the wiring is fine. If not, the open is between the O2 connector and computer somewhere -> replace wires.

It is possible there is a failure internal to the computer, but naw, not likely. I'ld bet on wireing damaged during the motor swap.


Cool thank man [cheers] I will try that and see. I never had a code till the engine swap. It been down hill since.