Alright guys after you finish laughing because I still run a UTEC..Here is my issue. I was replacing my stock manifolds with some headers when I noticed the manifold on bank 2 was white in color inside compared the the bank one that was normal burning color. I am running the Powerlab single turbo kit that uses one OEM 02 sensor on the bank 1 side manifold and none on the bank 2 side manifold. The OEM O2 sensor that is to go on that manifold is on the turbo downpipe, which I am assuming is used for the tuning of the engine. As far as I know the car was working fine for three years now. It did start to misfire a bit on idle some time back but not a great deal to really check it out. Now I know why it was doing this...Any ideas on why its leaning out on that side only? BTW there are no visible fuel leaks.

 

color doesnt mean its lean. your valve seals could be going bad.

could be a ton of things. what do your spark plugs look like?

 

Plugs look clean not lean looking...

 

Since you don't have an o2 sensor dedicated to that bank the A/F is probably all over the map (on that bank) in closed loop.

 

That makes sense...Just wants to make sure it wasn't anything bad with the tune or the motor...It does run lean on idle...and about 11.2 on WOT. Getting that initial black smoke puff now...didn't happen before either.

 

Do it right and get a wideband O2 sensor in each bank. Don't try to tune a VQ by looking at the spark plugs or the color of the inside of your exhaust manifolds unless you want to join the fail boat.