My dads 2002 infiniti qx4 recently threw a p0300 code so we had to try to solve the misfire problem. The code changed to p0304 I think so the first thing we tried to do was to change the ignition coil number 4. No luck. We also changed the fuel filter thinking that would solve the problem but nope. We picked up some spark plugs and we swapped it all and still no luck! Although the check engine light is gone at idle, the light flashes at 2k Rpms and if I let go of the throttle, it goes away. The sound of the exhaust at idle doesn't sound healthy at all and it has a weird smell to it. When we try driving it, there's like no power at all. Please post some suggestions on what the problem might be. Thanks.

Update:cleaned the MAF sensor, still no improvement.

Video: http://youtu.be/k7HljVrcN7k

A flashing SES light indicates cylinder misfiring, which explains the exhaust smell (raw fuel is being dumped into the catalytic converter and it cannot deal with all of it, and this damages the cat) and lack of power.

How many miles are on this QX4? Have you tried cleaning the MAF sensor? Use MAF cleaner spray only and disconnect the negative battery terminal before removing the MAF sensor's harness. It will be secured by 2 T20 Torx screws (possibly security Torx screws). The bottom of this article has more details about cleaning the MAF sensor.

Welcome to NICO!

Towncivilian wrote:A flashing SES light indicates cylinder misfiring, which explains the exhaust smell (raw fuel is being dumped into the catalytic converter and it cannot deal with all of it, and this damages the cat) and lack of power.

How many miles are on this QX4? Have you tried cleaning the MAF sensor? Use MAF cleaner spray only and disconnect the negative battery terminal before removing the MAF sensor's harness. It will be secured by 2 T20 Torx screws (possibly security Torx screws). The bottom of this article has more details about cleaning the MAF sensor.

Welcome to NICO!

Ok thank you:) ill go try that out and ill be sure to post here again if the problem is solved. And there's 109k miles on the qx4.

Aww no luck. I used MAF cleaner and cleaned the sensor but it's still the same. Check engine light is still on and idle is still bad. Here's a video I just took http://youtu.be/k7HljVrcN7k

What did you replace your coil pack with? a Flashing check engine light indicates possible (Probable) Catalytic converter damage.

zach7685 wrote:What did you replace your coil pack with? a Flashing check engine light indicates possible (Probable) Catalytic converter damage.

When I first scanned the code, it said that cylinder 4 was misfiring so I replaced the ignition coil in cylinder 4

Is the code still P0304?

What brand ignition coil did you use as a replacement? Did you use the NGK PLFRA5A-11 spark plugs as replacements?

Towncivilian wrote:Is the code still P0304?

What brand ignition coil did you use as a replacement? Did you use the NGK PLFRA5A-11 spark plugs as replacements?

The code is now p0302 and I used a duralast ignition coil I bought from autozone. And yes I used those spark plugs. Is it possible that my fuel injectors are bad?

What did you end up doing to fix this flashing check engine light?