2002 chevy blazer, sensor problems

[janie53]

The engine light came on, code said it was oxygen sensor. Replace sensor, light came back on, code came up saying it was same sensor. Replace it again, drove 8 miles , light came back on. Code says it is same sensor!Help, whats going on?

[ProTech]

Well, first of all, can you post the code you're getting? You should make sure you're replacing the correct sensor, as sometimes it can be confusing as to which is bank 1 or bank 2, or sensor 1 or 2.

If you're sure you've replaced the correct sensor, then it must not be a sensor problem. You could have a wiring issue going to that particular oxygen sensor, or a computer problem.

[janie53]

If its the wiring, what part do I have to buy to fix it? Thanks for any help you can give me.

[ProTech]

If it is a wiring problem, you have to repair the wiring. You don't buy a part to fix that. I'd still like to know what trouble code you had for which oxygen sensor, just so we can make sure you replaced the correct one.

[janie53]

The code said bank 1, I can't get my car inspected, the light keeps coming back on. How can I find out if it is the wiring?

[ProTech]

Can you please post the actual code number please? Not just what it says, but the actual code itself. If it's bank 1, that would be the driver's side of the engine...is that the one you replaced?

[janie53]

yes, it was on the drivers side

[ProTech]

Ok, so I'll assume you replaced the correct sensor although there are two bank 1 sensors, one before the catalytic converter and one after it. Like I said before, if it's not a sensor issue, then you have a wiring problem going to the sensor or a bad ECM. Not much really else involved in those circuits, it's pretty straight forward. Trace the wiring from the sensor to the computer and see if there are any problems like a short, a rubbed through wire, corrosion, etc. If not, replace the computer and have it programmed.

[janie53]

I'll checked the wiring going to the sensor, thanks for all your help.

[carriedi]

did you clear the codes after replacing the sensors? If you cleared the codes with a scanner and the same p0155 came back you should check the fuse for the o2 sensor heaters.