P0305 code

2002 FORD EXPLORER
107,677 MILES • 6 CYL • 4WD • AUTOMATIC
Avatar
RIVERS123
  • MEMBER
  • 1 POST
Hello my check engine light is on and I took suv to the dealer for partial code check and it said po305 cylinder #5 misfire detected so I wonder what is the cause or how can I fix the problem.
Dec 22, 2010 at 3:13 AM
Advertisement
Avatar
MHPAUTOS
  • CERTIFIED EXPERT
  • 31,937 POSTS
Plug, lead or coil if coil over plug ignition, faulty injector are the most common causes, start here.

mark (mhpautos)
Nov 16, 2019 at 2:22 PM
Avatar
CHOGIDOG
  • MEMBER
  • 1 POST
I have a 96 explorer with a 4.0l 4x4. I've been replacing a lot of parts to pass our state inspection and unfortunately, more problems have been creeping in as I fix others. I started with P0401, p0305, p0171 and sometimes p0113 and p0174. I replaced the plugs and wires, the DPFE sensor, cleaned the MAF, replaced the vacuum lines to the DPFE sensor due to some cracking and installed a wire tie on the IAT connection because the clip had broken off and replaced the fuel filter. At the same time I installed new inner tie rods and upper control arm on the passenger side and shackles on the leaf springs. I cleared the codes and took it for a test drive of about a half mile, when I returned and parked in the driveway, the water pump started leaking. I replaced the pump, topped off the coolant and warmed it up with no issues. Took it for a 45 min drive to return the fan clutch tool and a p0171 showed up, but ran fine otherwise. When my girlfriend took it to work, it started misfiring and blowing smoke. It now has codes p0304 p0305 p0306 p0171 and p0174. I know what obd2 says they mean, misfires on 4 5 & 6 and lean on banks 1 & 2. But does anyone know where I can start to fix them?
When I got to her work to take a look, I didn't see anything obviously disconnected like vacuum lines or plug wires. The alternator seems to a little noisier than I recall from earlier today and there's a puf-puf-puf (best imitation of a exhaust? leak) coming from the passenger side.
Dec 21, 2020 at 1:44 PM (Merged)
Advertisement
Avatar
RASMATAZ
  • CERTIFIED EXPERT
  • 75,992 POSTS
Lean fuel condition could be caused by one of the following below:

1.Vacuum leaks
2.EGR and PCV valve.
3.Low fuel pressure.
4.Dirty fuel injectors.
5.Mass Air Flow Sensor.
6.Oxygen Sensor.
Dec 21, 2020 at 1:44 PM (Merged)