Hey guys, I was wondering if someone could provide some insight on this:

I got a set of stainless steel OBX headers & y-pipe (eBay) installed, along with the two O2 sensors before the cat (in the exhaust manifold) installed, and a new cat.

I picked my car up from the mechanic and all was well. After driving it to work a short distance away, SES light came on. I went home and put my scanner tool to it and P0134 & P0154 come up for sensors in Bank 1, Sensor 1 AND Bank 2, Sensor 1 no circuit activity for both. I take it back to the mechanic and he connects it to his computer and says the O2 sensors are fine. He says I might just need an O2 sensor after the cat (that's where I get confused, why would I need that one it it's not giving me the code for that sensor?).

Do I need a new O2 sensor for the back after the cat? Or why am I getting those codes on the SES light?

Car information:
2001 Chevy Camaro
3800 Series II, V6, 3.8L Engine

If someone could help me out, that would be GREATLY appreciated. I saw another thread for a similar issue, but it went off on a tangent about whether the car had 3 or 4 O2 Sensors (Mine has 3 total!). Please let me know what you guys think. Thank you.

 

Checked the O2 sensors today and they seem to be fine. No wires frayed or whatnot. Might check the heater circuit fuse... if only I knew which one it was. lol

 

Sounds like you might need new O2 sensors, and remember that a dropped O2 sensor is a bad O2 sensor! Are you certain the sensors are installed properly? Did you replace them with new ones? Are the pigtail and connectors in good shape? Have you checked for exhaust leaks?

O2 after the cat (Bank 1 Sensor 2) is JUST for emissions, no other function -- you could put a Sim in there as an option -- Speed Inc. sells them.

 

what brand name 02 sensors. new headers have coating that will burn off from the inside and can ruin 02 sensors.

 

check they are not loose, my OBX headers had O2 bung a bit too big on one side, dont know why?? Anyways my sensor was loose so it was reading a lean condition although the leak wasn't enough to set a code?

 

Yea, that too. Could be other contaminants too like coolant, oil, rtv, etc.