Guys I have an 03 and I have been having problems like crazy, I have been throwing codes nonstop, the O2 sensors have all been replaced, the MAF the plugs PCV valve all replaced, no vac leaks, but I keep throwing a 171 for lean bank one and for the O2 sensor. Nissan has it now and they said that the guy is tracing wires WTF is going on and has anyone ever heard of this!!! Its the driver side O2 on the header

 

could all of these issues be caused by a bad cat ....meow

 

The catalytic converter is probably not your problem. Some things to check would be a faulty fuel injector or EGR valve. It really could be a lot of things so good luck; I hope your Nissan dealer can figure it out.

 

thanks for the info, I appreciate any advice I can get on this

 

we have access to a website here at my shop called all data....i just looked up the code you're throwing, and it cames back with 8 different possibilities for the code

-intake air leaks
-heated o2 sensor 1
-injectors
-exhaust gas leaks
-incorrect fuel pressure
-lack of fuel
-MAF sensor
-incorrect PCV hose connection

id check the wiring going to your injectors, and all your hose connections...hope that helps