To start off with, just obtained a Stage 3 RPM Tune. Spark plugs are NGK 1422s, less than 50 miles on them. Left them at the gap they come with which should be .024. Coils are original with 70k miles on them. Im not getting any CELs though Torque Pro is indicating small amounts of misfires on cyclinders 2 and 3, cylinder 3 being the worst at 7 for a 18 mile drive to work.

From Rpm range 1200-2000 (2k being when turbo kicks in) i can feel the slightest stuttering/jerking happening. Going straight maintaining the same throttle position and speed when testing i can feel it sort of jerking, feels almost like something rotational catching on something. Almost feels like a wheel hop. Its the worst at 2nd gear from 1100 to almost 1900 rpm. In 5th or 6th going 70mph I dont feel it really at all. Not sure what could be causing this, any ideas guys?

 

It could be the throttle body. It’s digital so it’s not smooth. My second R56 does this but not as bad as my R52

 

Yeah could be. Likely to fail at low RPM's as well since that would be the most likely used range--read as "worn out".
It shouldn't necessary be cylinder dependent though?
Crappy fuel, plain old clogged fuel injector/fuel starvation at the cylinder could be as well.

 

My fuel pressure is fine as I have been monitoring it convinced my HPFP will randomly fail any day. Atleast torque pro numbers seem fine. Cold starts are a bit rough, i can hear the engine almost die for split second then keep idling. Does that while parked and idling. Just not sure whether its as simple as an Coil replacement or something broke after the tune.

 

Providing an update to this thread, still having the same problems but have developed a new problem.

Now i cant build reliable boost. Loud pop when i was pushing 23psi and my air charge pipe popped off the blue middle section. No problem, fixed it but car couldnt build boost since. On cold start im getting at the most between -6 to -10 psi and can also hear hissing/venting during first bit of warming up, almost the same as a dumping boost sound. When driving in 4th gear and then attempting to build boost, i read exactly (-)1.00psi (read as negative) until the car surges then pushes maybe 10 psi then dumps it immediately. Should be building much more boost way earlier with stage 3. Thinking something is broken or worn out now, maybe diverter valve broke?

I have this on startup and when warming up

 

If you're getting misfires on cylinders 2 and 3, swap those coils with 1 and 4 to see if the problem follows the coils. About a year ago, I had two of my coils start acting up at the same time, and that was before my RPM stage 2.

 

Answer to this thread was bad O2 sensor causing engine to run too rich for spark plugs. Problem solved now.

 

This post was a fun read. I was about to point you towards the tune and plugs. I am glad you figured it out. This board was helpful for you! JK of course, This is a good reminder to keep it simple and focus on the basics.