Originally Posted by Major_Heat

I don't know if this may help any of you guys draw a conclusion to what is the problem. My scan tool has a function that allows me to view live data while the engine is running, here a list of data points I figured might be helpful. I can't interpret much of this stuff. Hopefully you guys can read this and have an idea of what may be the primary issue.

Temperature Data (Warm Idle ~800 RPM)

• IAT (Start): 28°C
  
• IAT Sensor (Current): 27°C
  
• IAT Voltage: 2.74 V
  
• ECT (Start): 64°C
  
• ECT Sensor 1: 71°C (1.00 V)
  
• ECT Sensor 2: 20°C (3.12 V)
  
• Catalyst Temp: 478.8°C
  
• Estimated Battery Temp: 18°C
  

Fuel System

• Direct Injection Fuel Pressure: 3870–4000 kPa
  
• Fuel Pressure Sensor Voltage: 1.15 V
  
• Injector Pulse Width: 1.44 ms
  
• AF Lambda Commanded: 1.01
  
• AF Lambda Actual: 0.90
  
• AF FB (STFT): 0.69
  
• AF FB AVE (LTFT): 0.77
  
• Air Fuel Ratio: 13.02–14.52
  
• Fuel Consumption (Idle/Stop Status): 8439 cc
  
• Fuel Consumption (City): 4533 cc
  
• Fuel Level: 7.84–8.10%
  

Airflow / Intake Data

• MAF Voltage: 1.45 V
  
• MAF Flow: 5.40 g/s
  
• MAP: 38.00 kPa
  
• MAP (Hi Res): 301.40 mmHg
  
• MAP Voltage: 1.18 V
  
• Barometric Pressure: 88.00 kPa
  
• Baro Voltage: 2.57 V
  
• FTP Sensor: -0.13 kPa
  
• FTP Sensor (Fine): 16264.50 Pa
  

Oxygen / A/F Sensors

• AF Sensor Signal (+): 2.20
  
• AF Sensor Signal (−): 1.82
  
• AF Sensor Current: 0.26 mA
  
• AF Sensor Impedance: 38 ohm
  
• HO2S S1 Heater: ON
  
• HO2S Heater Duty: 87%
  
• HO2S S2 Voltage: 0.92 V
  
• HO2S S2 Output Voltage: 2.47 V
  
• HO2S S2 Heater Current: 0.89 A
  
• HO2S S2 Heater: ON
  

Misfire / Crank / Cam Data

• Misfire Driving Cycle: 1.00
  
• CKP Noise: 0
  
• CKP No Pulse: 0
  
• CMP A Noise: 60
  
• CMP A No Pulse: 50
  
• CMP B Noise: 0
  
• CMP B No Pulse: 5
  
• CKP Pulser F/B Learn: Not Completed
  
• Idle Learn: Not Completed
  

Electrical System

• Alternator Circuit: 12.5
  
• Alternator L Signal: Low
  
• Estimated Battery Resistance: 9.30 mΩ
  
• ELD (Electrical Load): 16.50 A
  

Throttle / Drive-by-Wire

• Throttle Valve: 3.90°
  
• Target Throttle: 3.91°
  
• Idle Target Throttle: 3.94°
  
• TP Sensor A: 0.74 V
  
• TP Sensor B: 1.59 V
  
• APP Sensor A: 0.96 V
  
• APP Sensor B: 0.47 V
  
• DBW Stuck Ratio: 28.24%
  
• Engine Speed: 800 RPM
  

Other Data

• Spark Advance: 8–14.5°
  
• Knock Retard: 0.00
  
• Knock Sensor Drag: 2.51 V
  
• Knock Control: 1.50
  
• VTEC Pressure Switch: ON
  
• VTEC Solenoid: OFF
  
• Slip Ratio (Clutch/Start): 96–100%
  
• A/F Imbalance Measurement: 0.00
  

Just to recap where the car is at it’s still misfiring even after everything that’s been done. Plugs, coils, injectors, timing verified, burnt valve repaired, ECM reset with crank relearn, and even a new crankshaft position sensor. Compression is strong across all cylinders, so mechanically it should be sound. Despite that, it’s still running very rough. It won’t rev properly, shakes at idle, and it’s running extremely rich. The raw fuel smell is strong, like it’s dumping gas. Current codes are P0102 (MAF voltage low), P0172 (system too rich), P0301 (cylinder 1 misfire), and P0300 (random misfire). What’s odd is the misfire keeps moving. Before it was cylinders 2 and 4, now it’s mainly 1.
I’m just trying to figure out the right next step instead of continuing to throw parts at it.