Hey guys,
I have been having a big misfire issue since last August; and it's driving me crazy. I had 10k miles on my Fast Intentions kit when the issues started, and I'll list the steps I have taken to fix the issue. I have been in contact with Fast Intentions, Specialty Z, and a shop in my area to try and fix the issue, but no fruit yet.
First of all, the major issue/code has been P0302, Cylinder 2 Misfire, and the car has intermittent, very rough idles and cruises. Some times, the car will be perfect for 5-10 miles and then will have horrible misfires that bogs it down and ends up flashing the service engine soon light. It seems that the problem occurs after the engine warms up more than other times.
Other days, it will be constant, and then when the service engine light comes on, the misfires go away for an instant (like 10 seconds), and then it will come back. I also have been getting cylinder 6 misfire (P0306) and random misfire (P0300) codes.
I have done the following
-- swapped injector 2 out for a new one
--- swapped coil packs on 1 & 2 -- misfire stays on 2
-- replaced all 6 spark plugs with new ones
--performed compression test on 1 & 2 --- were normal.
-- replaced factory PCV routing with new PCV valves and breathers on the ends to vent to atmosphere, but it seemed to run worse like this, so I recently put Z1's silicone hoses on as factory replacements. When I first put these on, the car was FLAWLESS for 15 miles. Then the misses just came back. Almost like once the ECU adjusts the problem reappears.
Recently, a pending code came up: P2A03, which is upstream O2 air/fuel sensor bank 2. I'm wondering if the air fuel sensor upstream went bad... When would the car NOT rely on the O2 sensor for AFR? That would explain the misfires inexplicably going away for a few seconds/minutes.
Below is a pic of my old spark plugs, ordered 1,3,5 on the left, bottom to top, and 2,4,6 on the right, bottom to top. Plug number 4 seems to be the most blackened, but 2 is dark as well. What would cause cylinder 2 issues to transfer over to cylinder 4? The problem definitely seems to be with bank 2.
ImageUploadedByTapatalk1432522640.353929.jpg
Here is some recent freeze frame data:
Freeze frame report generated by Torque for Android
================================================== =======
Vehicle Manufacturer: Nissan
Vehicle Calibration ID: 11A39A
V3EV0A
Freeze frame information:
------------------
Fuel Status = 0 byte
Engine Load = 36.078 %
Engine Coolant Temperature = 188.6 °F
Fuel Trim Bank 1 Short Term = -8.594 %
Fuel Trim Bank 1 Long Term = 6.25 %
Fuel Trim Bank 2 Short Term = 14.844 %
Fuel Trim Bank 2 Long Term = 9.375 %
Intake Manifold Pressure = 13.343 psi
Engine RPM = 2,875 rpm
Speed (OBD) = 75.807 mph
Timing Advance = 23 °
Intake Air Temperature = 86 °F
Throttle Position(Manifold) = 17.255 %
Run time since engine start = 836 s
Distance travelled with MIL/CEL lit = 0 miles
O2 Sensor1 Equivalence Ratio = 1
O2 Sensor5 Equivalence Ratio = 1
Fuel Level (From Engine ECU) = 100 %
Distance travelled since codes cleared = 17.398 miles
Evap System Vapour Pressure = 0 Pa
Barometric pressure (from vehicle) = 14.649 psi
Catalyst Temperature (Bank 1,Sensor 1) = 1,076 °F
Catalyst Temperature (Bank 2,Sensor 1) = 1,076 °F
PID: 41 = 0
Voltage (Control Module) = 13.92 V
Engine Load(Absolute) = 36.863 %
Commanded Equivalence Ratio(lambda) = 1.005
Relative Throttle Position = 12.549 %
Absolute Throttle Position B = 17.255 %
Accelerator PedalPosition D = 27.451 %
Accelerator PedalPosition E = 27.451 %
End of report.
Any ideas would be greatly appreciated.