I had determined the bosch o2 sensor kept going out on my blazer causing it to run very poorly. I went through 3 bosch o2 sensors over 5 months of this issue which were under warranty until I finally bought the Delco sensor. With the SES on I replaced the sensor on the drivers side which was the bosch one. I drove to kansas, a 350 mile trip and the sensor remained on until I returned home a week later. On the drive home I was crusing at 70mph when the rpm's dropped suddenly and the vehicle lurched, making a sound that I would associate with a motor trying to escapetheblazer,and the rpms shot back up and continued crusing fine. Didnt do it the rest of the way. Now, a week later the SES comes on and off. When the motor is cold, the lurching is so frequent its almost chugging. As it chuggs, the temp gauge drops to 0 then as it chuggs again, it bounces back up to a quarter. This happens until the motor is warm at any speed under any load. This past weekend, I drove a hundred miles to deer hunt and the SES came on again and the same story. Lack of power, chugging when cold and very poor gas mileage. Got it home and it was idling very roughly. Next morning started it, SES was on, chugged when cold then ran fine while war and now the SES is off again and all is well. I know it will be back on soon and all the issues will come back. It's almost daily now. Why is this happening?

Codes are:

P0118
P0131
P0134
P0300
P1133

I know what the codes are. I have not changed the spark plugs since august, so its been quite a few months running rich, could the plugs be fouled and that be causing the symptoms? It's just so damn cold, I'd change them if it wasn't.

-Jon

Oh is bank 1 sensor 1 the drivers side pre-cat? Cuz thats the one I replaced with the brand new Delco.

 

Yes, B1S1 is the sensor on the driver's side between the exhaust manifold on the engine and the 'Y' on the y-pipe.

Just for my own thought process:
P0118 - Coolant Temp Sensor High Input
P0131 - O2 Sensor Circuit Low Voltage (B1S1)
P0134 - O2 Sensor Circuit No Activity Detected (B1S1)
P0300 - Random/Multiple Cylinder Misfire Detected
P1133 - HO2S Insufficient Switching Sensor 1

Now I'm assuming this is on your '98 ZR2 that we were discussing HERE. Anyway, there has to be something that is causing the fuel trims on the driver's side to max out. It is possible that there is a problem with the wiring. This is further evident by the coolant temp sensor code.

Further information on the ECT sensor:
It is possible that the power wire for the O2 sensor has shorted with either of the wires for the coolant temperature sensor. The wires from the O2 sensors are purple and tan, both with white tracer lines on them for a 2000. I don't have references for your '98, but I do not believe the wire colors have changed. I would fully inspect the wiring harness from the O2 sensor and ECT sensor all the way over to the PCM.

 

My SES has been going on and off alot recently. It was on today when I changed the spark plugs. I had the battery unpluged for about 20 minutes but the codes didnt clear. Anyway, the old plugs didn't look that bad but I changed them because I thought they might have fouled out. I drove back home with the new plugs and the SES still on and it ran fine until I was almost home. I was crusing at about 55 mph and the motor clunkedor chugged, it felt like I hit a pothole but the road was smooth. What could be causing the motor to stall momentairly like that?

 

Are the codes the same? Did you check the wiring as I suggested?

 

which side is bank 1?

 

Driver's side.

 

ok, i looked and couldnt find the ect sensor....could i get a better description than on the drivers side head above the exhaust manifold.... i have a 98 v6. i just cleaned the b1s1 o2 sensor and now the coolant temp gauge is cutting out and the engine is cutting out as well...

 

It is the only thing with wires coming from it between the valve cover and the exhaust manifold...

 

is it accessable without removing anything else?

 

You might want to remove the intake ductwork from the filter box to the throttle body.

This should help:



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