[zain1003]

i am getting a few codes and serious misfires.

at first misfires were just at high rpm.
now at 25% throttle its misfiring hard.

It is undriveable!

hpfp and injectors were done less than 3k miles ago.
walnut blasting less than 1 k ago.
walbro 450 was installed 100 miles ago.
FMIC was installed at the same time as walbro.

Not sure where to start, car is shaky and rough at start up. rough idle. after it settles I drive it and with barely any throttle it cuts out and then misfires and shakes hard.

2c9e is one of the codes thrown. I believe its post cat bank 1 o2 sensor.

other codes are cylinder injection cut off and misfires in 1,2,3,4,5.

does the post cat o2 generally cause misfires?

Any help is appreciated, I miss my car =( its been sitting for a couple weeks

[chili36]

When was the last time you did plugs? Where the also replaced along with injectors?
Have you tried swaping coil pack 6 to one of the misfiring cylinders?

[zain1003]

Originally Posted by chili36

When was the last time you did plugs? Where the also replaced along with injectors?
Have you tried swaping coil pack 6 to one of the misfiring cylinders?

I am sorry, shouldve included more info.

Plugs are newest part of the car. NGK 5992 plugs.

Also, I have gotten misfires on 6 before, just not recently. I just find it very hard to believe all the coil packs failed at once. but if its more likely than I understand I will swap them for new ones..

[DallasBoosted]

Originally Posted by zain1003

I am sorry, shouldve included more info.

Plugs are newest part of the car. NGK 5992 plugs.

Also, I have gotten misfires on 6 before, just not recently. I just find it very hard to believe all the coil packs failed at once. but if its more likely than I understand I will swap them for new ones..

What did you gap your plugs at?

How does your fuel pressure look after the pump upgrade?

[zain1003]

Originally Posted by DallasBoosted

What did you gap your plugs at?

How does your fuel pressure look after the pump upgrade?

Plugs were gapped at .025, not by me but by the tech that did the work at the performance shop.

Is it possible the LPFP was installed incorrectly? I have not logged fuel pressure yet

[DallasBoosted]

Originally Posted by zain1003

Plugs were gapped at .025, not by me but by the tech that did the work at the performance shop.

Is it possible the LPFP was installed incorrectly? I have not logged fuel pressure yet

Log low-side fuel pressure, and check to make sure your O2 sensors are in the correct banks. Did you do downpipes, or do anything with the o2 sensors?

[tphss]

Originally Posted by zain1003

Plugs were gapped at .025, not by me but by the tech that did the work at the performance shop.

Is it possible the LPFP was installed incorrectly? I have not logged fuel pressure yet

0.025 might be too large of a gap for the N54. People here recommend 0.022, that's what I used on my new NGKs last week and it seems to be very good.

I would say coils might be a good place to start now. I replaced all 6 coils and plugs last week, I had very similar issues to what you are describing but different codes (had misfire 5 and coil 5 codes).

[enrita]

Problem is the pump probably, log low pressure as already advised . Could also be low pressure sensor maybe. Can be tested with inpa