I don't know if this goes in this section but here goes.I have a 2010 L99 with 11000 miles on it. It has been running great. It has a Jannetty Tune, Headers, TB and a Vararam. It sits in the garage for a month sometimes without using it. The other night I took it out and it was running good when stopped at a light it started running rough, felt like I lost a plug, NO Code. When I got home still no light until next day and set a P219B and P174 which is Bank 2 is lean. I have check for exhaust and intake leaks, checked my oil catch can drain valve made sure it was tight. I installed 8 spark plugs also. I notice that all the plugs had oil on the threads. No valve cover leaks where is this coming from? They are not fouled with oil only on the threads can anyone tell me about this and could anyone give advice on the codes?

 

Jannetty tuned my car as well so I doubt he missed something in the tune. What kind of catch can are you running? How is it routed? How long ago did you install it? Do you have a breather on the can or your valve cover?