msmy300z

No, it never went away. I haven’t been able to resolve it since I decided to change the plugs. It wasn’t throwing a code until I fixed the boost leak. I assume the leak was a coincidental finding that I found trying to fix the original problem.

So I fixed the boost leak at the coupler and the issue was still there. I had hesitation and misfire P0304 with a PFFFF code. I have removed the plugs and checked the gaps (~0.029). I also swapped the coils between 2 and 4. Still the same problem and misfire P0304, PFFFF, and PFFFE. I assume that swapping the coil ruled out the pack. The issue is still only present with WOT. So finally, should I swap the plugs and see if it follows or do I have a bigger problem? I did not specifically inspect the #4 plug but did not see any damage to it when I went through all of them yesterday.

I did a boost leak test today and you all were right on the intercooler to throttle body coupling. I started at the intake and couldn't hold pressure for any amount of time. Hopefully this will fix the problem with hesitation. I ordered the Cobb part.

I checked with a ramp gauge and believe they were .03 dead. They are the NGK SILFR6B8. I also have a feeler gauge but don’t know how quality it is. It’s older than i am at 40. I’ll pull them out to check again and maybe tighten up to .028

I have not taken the plugs or coils out again but double checked my connections and everything seems seated correctly. I was concerned that the connection at the air box wasn't tight or flush but no change. Seems weird that a boost leak would develop after plug replacement but I did unbolt the motor mounts and lift ~1" for clearance. Am I right in assuming that I would probably get a miss fire code at times other than WOT if it was a coil or plug problem? Aren't the coils firing at the same rate at 5k regardless if the throttle is depressed? I did check the gaps and the coils looked fine. No noticeable difference other than some mild white corrosion on the bolt threads only. I have added another data log with boost, target boost, and boost error. This is with the Stage 1 again so boost targets are higher. The stock tune was realtime and it defaulted to this after an ecu reset. I am not hitting boost targets in the 4K+ and I notice the hesitation most in the mid rpm range. I don't know how to tell from a data log if the ECU is pulling boost for safety or if I am leaking as you all stated. My wastegate duty cycle decreases slightly at 4406 RPM which leads me to believe that it is trying to build more boost but can't? The wastegate duty cycle increase with RPM is consistent with the programmed boost taper? If the next step is to test for boost leaks, where do you recommend placing the tester? Do I have to start at the turbo inlet or can I place it at the airbox coupling? If I give up and take it to the mechanic, do you recommend a "specialist" or to take it to my regular mechanic? I assume that most mechanics can handle a turbo in this day and age? I'd rather not take it to the dealer will if I have to. Thanks again for the advice. datalog2.csv

Would boost error provide insight on a boost leak? The coils looked fine and the clips engaged fine. The plugs came from Rockauto and looked identical to the ones that came out. Unfortunately... I think all but one original plugs are gone. Tossed them when it initially seemed fine with the new plugs. I’ll look for boost leaks and maybe get anther log with boost error and fewer parameters?

I have 2010 with 74k on it. It was stage 1 93 now back to stock. I just replaced my plugs with stock NGK and everything went as planned. Started it up with a misfire and found a cracked insulator. This threw a misfire code and I replaced the plug. Everything is in working order now with no codes. It drives noticeably better than before the plugs except for wide open throttle. It has a hesitation in 2nd gear and higher on/off from 4k to redline. I had stage 1 on it and the hesitation was much more severe. It is still present at stock but less severe. This was not present before replacing the plugs. I don't see evidence of misfires on the datalog and no further codes. I have only noticed it at WOT. Thank you for any help. datalog2.csv

I am having trouble with my volume up and hands free steering wheel controls on a 2010 GT. I know that it is a documented problem and Subaru issued a TSB on the earlier models 2010 and 2011(?). It doesn’t seem too bad to swap the controls based n info here. I can’t imagine that the dealer would help me 9 years and 70k later... My problem is finding the part number for my year vs the later models at a reasonable price. The early ones have silver on silver controls and the later has silver with black buttons. The compatibility is listed separately but does anyone know if they are cross compatible for the entire 5th generation? I can get the later model controls for $45 shipped vs $120 or more for mine. Also, does anyone know if the buttons are interchangeable? I could get the cheaper (more reliable?) one and swap my current buttons over.