Larryrb

Have an o4 Silverado LS, 305 engine. Everybody's friend, the check engine light came on and I found a DTC P0135 from a code reader. Should be an O2 sensor. Bank 1, sensor 1. From what I've read this should be before any convertor on the driver's side. Replaced this sensor and within just a short time the engine light came on again. Same code. Checked the fuses under the hood. No problem there. I don't know what to do next.

You guys are such a great wealth of knowledge and have helped me out of situations before. Does anyone have any ideas on where I should go from here.

tech2

gm didn't make a 305 in 2004 model year.

with the ignition in run, engine off, check for power on the pink wire at the o2 sensor connector

country_09

When you changed the sensor out, did you reset the code? If you reset it and it came back on then if check for power but if you didn't reset it, the light will come on again and again no matter how many times you change it out.

Larryrb

I'm more than just a little embarrassed that I gave the wrong size for my own engine. This is a 5.3L. Duh.

I did reset (erase) the code after installing my new O2 sensor. However, I have not checked for power as you suggested.

I'll be checking for that voltage as you guys suggested. I notice that the old sensor does not have a pink wire. Perhaps this wire is on the truck side of the connector. In any case, I'll be checking for "any" power at that connector.

Will try to get this done today, and will be back to tell you what I've found.

That's a lot guys. I really appreciate it.