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john -aka eauto
john -aka eauto, ASE Certified Technician
Category: Jaguar
Satisfied Customers: 15384
Experience:  15 years as a auto tech
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Matt. I have a 2004 xj8. Two weeks ago i scan a code of

Customer Question

Hello Matt. I have a 2004 xj8. Two weeks ago i scan a code of P0101 mass flow sensor circuit A so I replace it with a new one from pep boys. A few days later the same code came back with a new code P0121 throttle position sensor circuit A and the car is going into limp mode every time i drive it. We have been going threw a raining period lately. Any thoughs?
JA: Does the vehicle hesitate during acceleration? Or maybe speed up suddenly when you aren't even hitting the gas?
Customer: Yes. When I let off the accelerator it will slowly accelerate and decelerate very slightly
JA: Are you fixing your XJ8 yourself? What have you tried so far?
Customer: yes. i have replaced the mass air flow sensor
JA: Anything else you want the mechanic to know before I connect you?
Customer: no
Submitted: 1 month ago.
Category: Jaguar
Expert:  john -aka eauto replied 1 month ago.

did you replace the tps yet?

Customer: replied 1 month ago.
no just the MAS.
Expert:  john -aka eauto replied 1 month ago.

any issue in throttle response?

Expert:  john -aka eauto replied 1 month ago.

does your scan tool show live data?

Customer: replied 1 month ago.
no i have no issues with throttle response and my scan tool dose not show live data
Expert:  john -aka eauto replied 1 month ago.

without live sensor data i would say a tps and exchange the maf its likley defective....but live senor data would tell us if its working or not

Customer: replied 1 month ago.
How much would a scan tool with live data run and which one do you recommend.
Customer: replied 1 month ago.
you think the MAS i purchased from pep boys could be bad
Expert:  john -aka eauto replied 1 month ago.

a good scan tool will run 3000 or more...and yes lots of maf from discount parts stores are junk out of the box...they are reman/ rebuild repaired units

Customer: replied 1 month ago.
Hello john. how hard is it to replace a TPS on my 2004 jaguar xj8 and do you have a diagram of its location. thanks
Expert:  john -aka eauto replied 1 month ago.

its a little buried about a hour