Let me start by saying that I've done the reading of almost any forum/thread that comes up on here and any other that comes up on google. I have a 2006 350z base with a catback exhaust and a cold air intake, other than that the powertrain is stock. I recently purchased these

https://conceptzperformance.com/czp-...ss_p_23429.php

However they worked for about 5 days. I erased the codes and went to get my vehicle inspected and the mechanic explained that it would only print me a temporary because it said that the EVAP and 02 sensors weren't ready. I was told to drive it for a few more days and bring it back. Then today the CEL/SES light came back on during my ride to work, which is easy driving not a lot of starting or stopping and pretty much 55mph the whole way there.

Here is where I need help and have a few questions I need answers to...

1.) What should both bank 1 and 2 read for voltage when monitoring on an OBDII scanner/code reader? (currently reading about .280-.420 for all 4 banks)

2.) Could it be that the spacers we're too much space and now the second bank is reading too low as far as voltage is concerned?

3.) Does anyone have any experience using a MIL eliminator/O2 sensor simulator. If so where can i get a set. I've been looking at this one on a mustang website but I don't know if it will work with my 02 sensor harness. http://www.americanmuscle.com/stmilel.html

Any information is greatly appreciated I'm kind of in a pinch here because my car is my daily driver and it only has a 10 day inspection. Thanks in advance!

 

Why would a catback exhaust facilitate the need for the spacers?

 

agree, a bolt on cat back shouldnt cause a cel. are you putting them on factory cats?

 

I thought the same thing, the cat on it looks stock! Although it did go through my head that it could be a HFC setup that looks stock or something like that. I will try to take some photos the next time I'm underneath it.