CEL after header install.
 

Well, let me start with a list of what's done to the car pertaining to the problem.

Afe stg2 intake
MD isothermal plenum spacer kit
Long tube headers
Secondary o2 sensor spacers
Magnaflow Xpipe
Vibrant resonators
Rear section from hks knockoff catback.

Problem is I am getting a CEL on startup with the same 4 codes. 2 codes that trip the CEL are:

P1168- sensor 1 bank 2 open/shorted/faulty connection
P1286- sensor 1 bank 2 circuit

There are also 2 pending codes that arise:

P1288/P1289- sensor 1 bank 2 circuit response time slow.

Now, the car starts up right away and runs perfect, but every time I start it these same 4 codes pop up. Once I clear them, they will never come back. I've driven 6+ hours from MN to ND multiple times after clearing them and the CEL won't come back until you shut the car off and restart. Is there some sort of startup parameter that it's not seeing right away or should I think about replacing the sensor at S1B2? Or is this just a product of the long tube headers that I need to accept?

Your primary O2 sensor is either damaged, dead, or unplugged.

On a side note you really need a tune with those mods..

They will stay off when you clear them...but as soon as you restart it goes through pending codes/start checks and pops the CEL again.

You either have a bad O2 sensor, or a bad wire going to the sensor

Thanks guys, going to swap out the sensor with a known good one this week to see if that cures it.

Also the tune is next on the list. Wanted to get all the mods taken care of before hand because the closest Osiris tuner to my knowledge is about 6 hours away from me.

Sounds like bad sensor. Easy fix.

Yea that's what I'm hoping for.

No need to go that far and get on the dyno with someone who may or may not even understand how to properly tune a VQ... as long as you don't have an 03 you can do everything remotely with datalogs, reflashing the car yourself with maps made by an Uprev protuner

^^how does that work??

Its really easy. You just buy the Osiris standard kit from a reputable protuner which includes an Uprev OBD2-USB cable so you can reflash the ECU as well as datalog on your own, then have the tune done remotely based on datalogs that you record while driving around. For your typical NA setup you'll get 95% of the performance of a dyno tune, at a much better price, and a heck of a lot more convenient. Plus you get the reflash cable so you can reflash updates if you ever need to, as well as reflash back to stock and use it on a different vehicle or sell it used later on. I've tuned a ton of cars this way and everyone was more than satisfied. :DOMO: