Misfiring after CBE install

thangcu35

Hi guys, I'm a new member and just got my Z this last weekend. It's a 2012 with 20k miles. It has K&N drop in filters when I bought it from the dealer, everything else is stock. It drove fine and smooth. I decided to install FI CBE 2 days ago and this is when the problem begins. Immediately after installing the cat back, I reset the ECU and took it out for a test drive and these are the symptoms I'm experiencing.

- When it revs above 5k RPM, it runs out of breath, the RPM could barely continue climb. Noticeable power loss. More severe with higher gears.
- I hear some weird pinging noise from the motor almost like detonation when the above occur (I run 93 premium, fresh gas). It might be misfiring/breaking up and I'm interpreting it as knock.
- The SES light also begins to blink and then disappears after a few seconds. I assume this is the ECU telling me that it detected misfiring sequences that could potentially damage emission comp. etc catalytic converter.

If I repeatedly do the above for a couple of times, the SES will remain lit and pop a P0300 code. If I do not rev it up high (WOT) and drive it normally, the SES light will not blink or throw any code. I have also tried to reset the ECU and allow it some time to relearn the fuel trim, but after 50 miles it does not show any sign of improvement. I honestly don't think a CBE can cause this much airflow difference to create a misfiring/leaned out condition, especially when the intake is relatively stock.

I have also tried cleaning the MAFs with CRC MAF cleaners and nothing changed.

Since the car is still under OEM warranty, I will bring it to Nissan and let them diagnose the problem. I'm wondering if any guru has any further insight into this issue. Here is a picture of the Z.