Ok, here we go again. This time we are dealing with my 09 XF 4.2. I am now throwing 0171 and 0174 constantly. Been thru this with my s type and I rely on that learning experience that many of you contributed to.
But in this case, the fuel trims are behaving exactly the opposite of what you all taught me with the s type lean codes. That is....that 0171 and 0174 are ALMOST always attributed to vacuum leaks, with a few other possible causes such as poor fuel supply, bad mafs, air filter etc. As i was taught with the s type, the CLASSIC symptom of an air leak would be ltfts that sit high and immediately drop upon application of throttle. IN THIS CASE....my fuel trims are doing exactly then opposite. That is at idle both the stfts and the ltfts are slightly negative and do not move. STFTs are at about -2 and LTFTs are sitting at -10 at idle. However when out on the road, and upon acceleration, the ltfts immediately rise to maxed out on my torque app at +20 while at the same time the stfts immediately drop by a corresponding -25 as if to compensate for the increased ltfts. EXCEPT FOR SOME APPARENT INSTANT WHEN ALL 4 FUEL TRIMS ARE CRAZY HIGH ENOUGH TO TRIP THE FAULTS. As soon as foot off pedal the ltfts drop and stfts go back up. All 4 trims seem to hover around 0 ish at cruise speed but i have to say that other readings on the obd app are haywire....fuel pressure fluctuating wildly as is the rpm even though the rpm fluctuation is not felt when driving.
So gang.....what are these fuel trim behaviors indicating to the experts here? I changed the air filter, mafs and fuel filter.
I will now attempt to paste a freeze frame of last fault occurrence.
Freeze frame report generated by Torque for Android
================================================== =======

Vehicle VIN: SAJWA06B19HR24463
Vehicle Manufacturer: Jaguar
Vehicle Calibration ID: 8X2

Freeze frame information:
------------------
Engine Load = 67.451 %
Engine Coolant Temperature = 185 °F
Fuel Trim Bank 1 Short Term = 27.344 %
Fuel Trim Bank 1 Long Term = 20.312 %
Fuel Trim Bank 2 Short Term = 21.094 %
Fuel Trim Bank 2 Long Term = 20.312 %
Fuel pressure = 51.778 psi
Intake Manifold Pressure = 13.198 psi
Engine RPM = 1,817 rpm
Speed (OBD) = 78 km/h
Timing Advance = 16 °
Intake Air Temperature = 68 °F
Mass Air Flow Rate = 39.49 g/s
Throttle Position(Manifold) = 34.51 %
Air Status = 0 byte
Run time since engine start = 278 s
EGR Commanded = 0 %
Fuel Level (From Engine ECU) = 38.824 %
Barometric pressure (from vehicle) = 14.069 psi
Voltage (Control Module) = 14.062 V
Engine Load(Absolute) = 52.941 %
Commanded Equivalence Ratio(lambda) = 0.972
Relative Throttle Position = 22.353 %
Ambient air temp = 62.6 °F
Absolute Throttle Position B = 47.451 %
Accelerator PedalPosition D = 33.333 %
Accelerator PedalPosition E = 41.961 %

 

That looks like after less than 5mins driving the coolant was up to 185F. Say if that wouldn't be right.

At those revs I can't see it being an air leak but perhaps a wacky MAF reading or low fuel flow or, well anything to account for why the PCM is desperate to add fuel.

As there are multiple O2 sensors I think you can rule out them being faulty (no codes and with so many they can't really all be bad in a consistent manner to fool the PCM).

So... the PCM is seeing something it does not like at the O2s - too much O2 - and as I say desperately trying to get more fuel in because lean running is an engine killer.

If it's happy at idle then you can rule some things out but at the very least I think the ones I mentioned are possible.

 

thanks for responding on this Jagv8. Appreciated. it does seem happy at idle. at idle, the fuel pressure seems to be sitting pretty steady at 43-45 psi. trims all close to 0 within a few points. But I have gotten an 0116 a couple times which indicates something with temp sender voltage? As far as trims, the wackiness starts when driving and accelerating. with gas pedal, the stfts go to -25 while simutaneously the ltfts max out at +20.5. I dont get that. I thought ltfts only reacted more slowly after a time and based on stfts. why are ltfts indicating they are dumping fuel while the stfts seem to be trying to compensate by restricting fuel. Also, the fuel pressure goes completely haywire in gear and accelerating. Instead of sitting steady on a value, the fuel pressure begins scrolling wildly between low 40's to upper 50's so quickly that no number value is believable. And I notice that exhaust fumes smell very gassy at idle in the garage.
I would likke to try a few simple remedies before taking to dealer. They already quoted me $370 just to smoke it. Criminal.

 

I wouldn't smoke test as it doesn't look at all like an air leak.

The values you posted are +ve for both STFTs & LTFTs. If you've seen a mix of big +ve and -ve and those other issues... it's very abnormal so you're not likely looking t any of the typical things.

A bad fuel pressure, whether true (bad pump / filter) or not (bad sensor) would cause a big upset.

It definitely needs the ECT to work and be consistent so that P0116 makes it worth investigating. And maybe replacing - they're pretty cheap sensors and it's maybe easy DIY.

Check the electrical stuff in case some of these sensors etc share any wiring because such as a chafed harness could cause all manner of wacky stuff.

An indy rather than dealer may be a good idea, especially if they've lots of experience going back years.

 

Thanks again Jagv8 for responding, and I hope you continue to help me. I have a good jaguar indy nearby, but honestly, I feel very concerned about letting anyone touch this car (other than dealer) (unfortunately) because if you recall, this is the vehicle that inexplicably blew up $5,000 worth of communication components when I simply change the car battery. And yes, I have changed car and boat batteries my whole life. I'm afraid if I take to indy, and the car blows up again, I will be stuck in a finger pointing contest. If a dealer blows it up, maybe I can hold them responsible??? BTW, after $5,000 replacing 2 keys, instrument cluster, antitheft module, fuse block (inside the passenger side), the dealer never did get the new keys to be recognized by the docking port and says the factory technicians cant help.
Anyway, back to current issue....at idle, all 4 trims are negative, fuel pressure is about 43 psi and maf reading about 9.3 whatever that is. in neutral with rpms up to 2300, the fuel pressure goes up to about 45, the maf jumps up to 25 and the ltfts go up to double digit +, while the stfts drop further -. The exhaust smells very gassy. It seems like for some reason the ltfts are seeing massive fuel dump, while at the same time the stfts are taking away fuel. How can that be? I have now driven the car several cycles since last cel, and I have pending 0171 and 0174, but for some reason it has not yet tripped to hard fault. I know I'm asking a lot of questions, just trying to get a better guess at what might be going on before I have to pay for help. BTW....I actually think the dealer (Jaguar-Lincoln) that I have taken this car to is either incompetent or eager to take advantage,,,,, and I hate to think is there something they did when fixing the computer issues that have led to this problem. It was not doing this prior to them working on the car and my obd scan tool had shown no codes and all monitors complete and good prior to them having my car. It seems ridiculous to charge $370 to do a diagnostic on these lean codes, and probably still be guessing.