Need help on 05 Cayenne base OBD P0203, P0300, P0303 & P0304
 

Hi All,

Since last week, my 2005 Cayenne base start to get misfire vibrating, acceleration power lose and engine light pops up.

after replacing all coils and spark plugs. The OBD code P203, P300-P305 still shown on my obd checking randomly ( the cylinder 3 misfire always exist)

Does anyone have any idea whats going on with my car.

Many Thanks.

yckong922

I believe P0203 is for cylinder #3 injector.
Make sure the injector is plugged in. Maybe try swapping it with a different cylinder, if the fault moves, you need an injector.

P0203 is injector #3 open circuit. Plugged in properly is first and if you want check the injector terminal 1 to 2 for resistance. It should be 11-13 ohms at 72F. The DME controls the ground circuit and battery voltage with key on is at terminal 1.

I had a wire going to my ignition coil that was touching the metal cover and it was starting to darken/melt. Also, found cylinder 3 spark plug was loose, threads were good and so was spark plug. I just re-torqued it and my problem went away, it was not the wire as I initially thought. Good luck.

Hi, yckong922
Did you solve your misfire problem already?
I am having same problem on my 2004 Cayenne Turbo.
I had Injector connector disconnect problem on #3 cylinder checking by OBD and fixed it.
But still have problem and current OBD code is following
P0300 507 Misfire detection, P0301 508 Misfire, cylinder 1, P0305 512 Misfire, cylinder 5, P0306 513 Misfire, cylinder 6 and P0308 51? Misfire, cylinder 8.
I swapped Coil between Good and bad cylinder but no change.
Checked #5,#6,#8 cylinder plugs and was wet.
Replaced by new one but same thing.
O2 sensor and Flow Sensor seems ok since no OBD code appeared.
I have no idea what happen on my cayenne.
Feels something wrong for Fuel flow stability may be bubbles in Fuel Rail? or Alternator become weak? but not sure.
Please let me know how did you fix the problem.
Yagura6120

Check your fuel pumps. Pull fuse 13. Then fuse 14. Shutting off after each pull to isolate. Likely the primary pump (left) as a result of a clogged fuel filter. Replace filter and pump.

Sorry, after fixed my problem I haven't check this thread.
For reference to whom has similar problem, I just want tell you what was a issue and how solved the issue.
The problem was due to Intake Manifold gasket seal degradation at some portion and started have leak. I tried to tighten bolts for Manifold but it makes more leaks due to distortion of Gasket.
It was big pain to replace the gasket seal but finally solved the issue.:)