O2 sensors

hey guys, to start out i've got a 2000 camaro z28 with headers and an offroad y-pipe. today the service engine light came on and when i checked it the code was P0161. my question is that i don't know which sensor that is and what effect it's going to have any ill effects on the engine or the way it runs, performs etc. i've had the exhaust on the car for a while so im kinda stumped as to why it is all of a sudden coming on if in fact having no cats is the reason the light came on. thanks for any advice or explanations you guys have.

-Chris

P0161 O2 Sensor Heater Circuit Malfunction Bank 2 Sensor 2

Google is your friend.

Bank 2 I believe is your passenger side, Sensor 2 should be the after cat O2.

i belive that could be cause u cut off your cat if its the sensor after the cat...now im no expert but i asume that if the cat is gone that sensor is reading a exaust too rich w/ fuel but i think for your car they sell a sensor to plug in there to fool it into not throwing a code check out summit they should have it.

I just read the code, and looked up it from there. I missed the offroad Y-pipe part.

It is because there are no cats. Are the rear O2's even still in??
Have the rear O2 codes deleted, or get O2 sims.

ok, here's the scoop... i got under there the other day and was takin a look around and the guy who owned it before me that had put the exhaust on had put O2 sims on it but that one that the code said malfunctioned, the O2 simulator had gotten jarred enough during a shift (which is when the light initially came on... 1-2 shift with a shift kit) that the connection was broken however luckely it didn't come off. so i connected it all up and everythings goin good.....

i really appriciate the help guys, thanks.