Hello! Turned on my jag today (2003 STR, 128k miles) and saw a “restricted performance” message on the dash. Seems to be driving exactly the way it was before this message popped up. Went and got the codes for the check engine:

P0332: knock sensor 2
P0442: emission system (this code been on here for over a year)
P1000
P1260
P1552
P0191
P0455

Wondering if anyone can give me any advice on what could be causing this and how serious/easy it will be to fix. Thank you in advanced

 

Hi, I am not sure about the other codes you have, but if you know that you got a knock sensor fault message, that would be worth looking at. When I bought my XJ8, it came with restricted performance (plus I could not exceed 3000rpm), I connected a diagnostic scanner and it told me it's the knock sensors. I swapped them and problem solved.

 

P0442: Evap leak detected - small
P1000: OBD system check not complete since last memory clear
P1260: Security input malfunction
P1582: Flight recorder data stored (need dealer level software to read this...)
P0191: IP circuit sensor range/performance
P0455: Evap canister purge valve circuit short-circuit.

So, it looks like all the OBD flags have not been set due to your knock sensor, fuel rail pressure and purge valve issues. Besides checking on the knock sensor(s), do you know the last time the fuel filter was changed? If not, change it! Purge valves are a fairly common failure point on older S-types (and they are all older now) and are simple to obtain and replace.

 

DTC guide

 

Make sure that all codes are erased and then let them reset before troubleshooting anything. You easily could have "Historic" codes that are no longer valid. Start with a fresh erased system and go from there.
With code P1000 that means the codes have been reset at some time in the past and the car is now trying to set all the readiness monitors. So you might have all valid codes right now.
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