Just went back for vacation yesterday, everything is fine.
But this morning went up an amber light showed Restricted Performance and without check engine light.
It disapeared when my car's speed over 90KM for a while and showed up again when idle.
I can not over 3000RPM, once I reach at 3, it will shake a lot. The Scanner shows No.1 cylinder too lean sometime, theres no other codes.
Mess air flow? Or any idea?

 

Number of code is???????????

 

Sorry I forgot to write it down

 

Not hard to do, if you want to play at fixing your toy yourself.
Buy a code reader, that can read Jaguar codes.
Great investment, a basic tool to have!

 

Code P0171, P0174

 

P0171 Left-hand cylinders combustion too lean
P0174 Right-hand cylinders combustion too lean

In both cases the following are given as possible causes:

• Air intake leak between mass air flow (MAF) sensor and cylinder head
• Fuel filter/system restriction
• Fuel injector restriction
• Fuel rail pressure (FRP) sensor fault (low fuel pressure)
• Low fuel pump output
• HO2S/catalyst monitor sensor harness wiring condition fault
• EFT sensor fault (low fuel temperature)
• Mass air flow (MAF) sensor system, <<309-00>> For fault (low intake air flow)
• Exhaust leak (before catalyst)
• ECM receiving incorrect signal from one or more of the following sensors; ECT, MAF*, IAT, fuel rail temperature

 

So I used my SDD to see, only shows P0171&P0174.
Maybe I should replace MAF first? Because I did not see any other codes comes up.
But the fuel pump output, I feel my car has more power when the tank is full...... is that my psychological problem??

 

Check fuel trims (many threads with details) rather than parts-swapping.

 

How many miles on the Jag?

 

Chased my vacuum leak down to those eight pesky rubber gaskets inside the intake manifold.
The car always ran great, but the check engine light kept coming on till they were replaced.

 

did you ever resolve your problems ?......if so how?

 

Sure, fuel system is fine.

 

99211 miles only.

 

I used a screw driver knocked my MAF for few times, the light went off sometimes.
So I ordered a new one and replaced it yesterday, the light never show up today.
But I dont know does it fixed or not, it seems solved but not sure.
The code vanished.

 

Good sign so far;

 

 

codes P0171 PO174 ..ervice guy has replaced sensors /fixed seals etc....BACK TO GARAGE ...4 times in 3 months HE clears codes and I drive 20 mins and engine light and amber warning come back on!

 

Clearly he is useless. Persist if you like.

It needs proper diagnosis and then a fix.

DIY or find a competent tech.

To DIY read the many threads on those codes.

 

JagV8 gave you some great advice, heed it.
Get off your rump, get a scanner, and get busy.
Unless your wealthy, & lazy, then find a decent tech.
They are a car after all, most of us feel good about d i y, and the money it saves.