We have an 03 S Type 3.0 that has been here three times with same codes,
P0300,P0301,P0303,P0308,1313, and 1316. While the vehicle is here we have no misfires and no codes,no vacume leaks, the vehicle has been driven 30 + miles every time here, ( no codes no miss ) customer takes vehicle and within 2 days the light is back on with same codes and customer says it runs great. Extended warranty paid for coils, and we have also done a power flush.

Thanks

 

The usual suspects are the two IMT O-rings. The yellow-colored factory O-rings shrink, degrade, and cause misfires. The new-and-improved replacement green-colored O-rings solve the problem. Many threads here in the S-Type section about it....

 

P0308 is not good for a 3.0 as it means cyl 8 and the 3.0 only has 6....

 

Ha I saw that one 2 , I believe he means #5 not 8.

Anyways I am with Jon on this one, check the IMT O-rings first:
https://www.jaguarforums.com/forum/s...ck-pics-49214/

Sometimes when the IMTs fail as in my case there were no codes and such either.

Next to check would be the "camshaft vent tube" the green color coded vacuum line in this thread: https://www.jaguarforums.com/forum/s...ck-pics-49214/

Since I assume its cylinder 1,3 and 5 (US passenger side) its one of the above 2 mentioned.

 

oops mind was somewhere else sorry,correct 5 not 8
tunning o rings replaced late last year
I will check the vent tube
thanks

 

Also check the air filter housing. All seals must be skin-tight. If someone has cracked it while changing the filter (very common) or installed an ill-fitting filter, that causes misfires as well....

 

Errr..... When it is all one side guys, remember my plight???

Bobco.... Take the car out on a clear open stretch and floor it.. and I mean FLOOR it... Has she revs up to the red line I can almost promise you will get a stutter and "restricted performance" light.. and the codes you are describing.

That is what happened to my car when one of the catalytic converters failed.. It took the Dealer capturing live data with me driving to actually figure it out...

Same thing.. It would drive fine and not miss at all.. Untill you gave it the beans..

 

Jeff, could be that too. Thanks for the reminder.