Originally Posted by hall_stephenk

I recently purchased a 2003 Nissan Altima 3.5SE with the VQ35DE engine. Within a week it stared throwing the P0011 code as well as a P0300 (multi-cylinder misfire). I definitely suspect the P0300 was caused by the P0011. Following Brett's recommendations, I was able to "easily" (based on my comfort level) remove the IVT solenoids and clean them out with WD-40, brake cleaner and compressed air. I went ahead and removed both but Bank 1 (closest the firewall) was definitely the culprit. Even though the solenoid activated when I applied 12V from the battery, the valve was stuck in the "energized" position.

Put it all back together tonight and I sure could tell a difference. No more rough idling and it seemed a fair amount more power. Just smoother all the way around.

For those wondering, I did just change the oil as well. I went with Mobil 1 5w-30 EP since it seemed to be the lightest 30 oil Mobil 1 offers. I'm wondering if the previous owner used a heavier oil and the lighter one moved some stuff around and gummed up the solenoid to the point of sticking.

Hope this helps others try this procedure. Could save you some time and $$$'s!

Originally Posted by sparks03max

Warning: I skipped all the other replies in this thread.

Brett, do you have the crank case breather disconnected from your intake? If you do, but have not also disconnected it on the rear valve cover where it connects to the rear of the intake manifold, then you have a perpetual vacuum leak during warm idle and general low throttle conditions. This could easily cause a rough idle (normally after it's been idling a while) and a misfire code from running too lean.

Just a thought...