As a longtime Jaguar driver I'm enjoying the 2002 XJ8 but mystified by occaisional codes, especially this series. Three times in the last couple of weeks the car has rough starting, only running while goosing the pedal a few times......then it's smooth as silk; runs smoothly and efficently for days (25 mpg!). Still the dreaded "restricted performance note and amber engine light. The codes read PO172, PO175, PO301-8, P1316, & P1111. I know what they read, except the last one, but am concerned about driving the car to a service facility which is an hour and a half away.
In the meantime I'm driving the good old dependable 6 cylinder Jaguars, but hate to give up on the 8.
Any wisdom will be enormously appreciated!
Submitted by stevejag@sbcgl… on Thu, 04/11/2013 - 10:06
Michael,
Those codes aren't really mysteries to someone that knows your Engine Management system.
P0172 and P0175 indicate the system is running excessively rich, as detected by the Oxygen Sensors.
P0301 through P0308 are detected misfires on all eight cylinders.
P1316 says the misfires are severe enough to cause excessive tail pipe emissions well above the normal limits.
P1111 is not a fault, but an indicator that all the component monitors have completed their tests since the codes were last cleared. If they had not all run, the code P1000 would be in it's place.
The excessive richness is likely the cause of the misfires, and will require some diagnosis to determine the cause. Could be a few things, failed Mass Air Flow Sensor, Fuel Pressure Regulator or even a plugged air filter. This can even happen if the engine has been flooded recently. That can put fuel in the oil and then it gets drawn into the engine through the breather system.
As long as the car is on one of those smooth running peroids, I wouldn't worry about the drive to a service shop.
Good luck!