2004 Cayenne-S misfire cylinder 1, 3, 8

[paulwu]

Hello all,

Need your guys help here. The 04 Cayenne-S was running fine but all sudden losing power while doing a parking with trailer. Idle very rough, low and smell fuel from the exhaust.

Got the code of p0300, p0301, p0303, p0308 they are the multiple misfire and cylinder 1, 3 & 8 misfire.

What I have done already below in sequence:

1. Changed all 8 spark plugs new
2. Changed all Beru coils new.
3. Changed new battery.
4. Disconnect the coil connector 1 & 3 while idling; the same rough shaking; guess there were no spark or signal
5. Swapped camshaft position sensors bank1 and bank 2; was guessing it could be one of CPS bad.
6. Checked each coil connector and power; all are fine.

All resulting in the same things; erased the codes each time but came out the same.

What else can be?

Being doing many research and there are things found that could be; but not sure how to check:

-DME?
-Fuel pump? not enough fuel pressure...but why only 3 cylinders misfire?
-Compression test..can't image why and suddenly if I have 3 cylinders down?

Any input will be great appreciated!

Regards,

Paul

[island911]

scratching head....

If it were fuel pressure I would think that misfires would be all over the map.

I would check the injector leads for signal. ...check connections...?

[fintstone]

Vacuum/air leak of some sort.

[paulwu]

Thanks for the info! I got the car running after rev the engine 5k 3-4 times then suddenly it is back. I believe it is the fuel issue; either fuel pump or injectors blocked. will keep checking.

[ninelevenick]

Did you clean the mass air flow sensors? Have you recently used a fuel injection treatment?

[paulwu]

Originally Posted by Snipernick

Did you clean the mass air flow sensors? Have you recently used a fuel injection treatment?

I didn't clean the MAFs; but since it suddenly return to normal now I am driving it full tank with fuel injectors cleaning treatment in it. Hopefully it was just the bad injection. So far being 4 days and running smoothly..just feel much less power with the addictive.

[jfort]

04 S. 184K miles. New plugs. New fuels pumps. Missing. Code misfire cylinder 8. Just replaced all coils. Still rough. Same code after reset. Any ideas?