misfire on 4,5,6 cylinder
 

Guys ,
Can anyone guide me in the right direction ? I have a 99 Boxster with fault codes
P0300 , P0304 , P0305 , P0306 , and it is undriveable.
On the Autel OBD reader it also says Fuel Sys 1 (CL) I presume this means closed
and on Fuel Sys 2 (OL) I dont know what that is.

I have not checked coils or the MAF , I just wondered if this fault has a easy/common fix.

Cheers C

check spark plugs
 

I had similar codes, check plugs.

Also changed o rings on my engine.

Cheers will give that a go.

The codes
 

– contaminated, faulty or wrong spark plugs
– Contact resistance
– Loose connections

But when you get to the diagnostic manuals for the '00-'04 Boxsters you also get cam timing . The fact that the "bad" cylinders are all on one side leads me to suspect this.

But lets start with some questions...

Done any work on the car lately?

Brand and model of plugs? When you pull them what do they look like?

How old are the O2 sensors on that side?

Is this car stock? Have you done any mods?

Any reason to think the cam timing chain jumped on one side (can be IMS caused)?

Thanks Mike ,

Will check plugs etc soon , No work has been carried out on it lately.

And the misfire has just gradualy got worse over the last 200 miles.

I have only owned the car 9 months and the sevice record is very vague.

There is no record of O2 replacement , so will start with plugs.

Hope there is not a problem with timing chain.

Cheers

C

Sounds like the IMS drive sprocket has slipped on the tune for bank 4-5-6... It's a fairly common issue that throws the cam timing off.. Have the cam timing checked and reset as required.