I have a 95 blazer with the service engine soon light comes on and will not go off. I had the code pulled and it was the bank one sensor, however the mechanic that looked at it also said the sensor was reading fine. I have no idea where to go from there. Also my oil pressure gage falls into the red and the check guages light comes on when I stop. I have had a new sending unit put in and also had a mechanic put a guage on it and he said the oil pressure was fine. This is a new rebuilt 4.3 (w) and I don't want to ruin it. Any suggentions?

I don't know much about the computer, but with the oil it is probably just a faulty sending unit. Youll really want to get that 1 fixxed fast before your new motor really is low on oil

It isn't running low on oil, the sender is just faulty.

He just needs to go to the mechanic and have them install a new one.

What was the code that you were getting? Bank 1 Sensor 1 tells us nothing.

It isn't running low on oil, the sender is just faulty.

He just needs to go to the mechanic and have them install a new one.

What was the code that you were getting? Bank 1 Sensor 1 tells us nothing.


the code was P0420. the computer they hooked it up to was showing the temperature at which the sensor was performing at and they said it was normal.

The mechanic just put a new sending unit on. Do you think the new one is faulty?

There is two problems here, one is the O2 sensor, and the other is the sending unit.

Depending on the time you got the sending unit replaced, it should be still covered under warrenty if it is still defective.

The other problem is the O2 sensor just before the cat. It needs to be changed. It is worn out.