I suspect my left side MAFS is on its way out. Pulled the codes (cannot remember them ) but that is what comes up. Ordered a new one from Rock Auto, Installed it (as per instructions) and it runs rough on start up. Is this a normal condition or a relearn or is something amiss?

 

Not normal.

Two things come to mind...

Did you plug everything back in and tighten all clamps on the intake tract?

Did you clear the codes after the new MAF was installed?

 

Everything was tightened up and the battery was disconnected for the change.

 

Disconnecting the battery won't clear a code from a hard fault or fool a computer on an OBD-II vehicle. Take it to Autozone and have them clear the code if you don't have a Bluetooth dongle.

When I disconnected my MAFs to see if my AutoMeter Dashlink reads IAT2, the car ran for about 30 seconds without the MAFs plugged in, and I had to go in with the Dashlink to clear the code.

I'm assuming, too, that yours ran fine before the replacement, other than throwing the bad MAF code? That code is a hard fault and will be stored for a very long time unless you clear it.

 

I do have have an ELM 327 so I will try that to see what happens. Thanks for the advice. When I change the MAFS on my 2000 XK it was a no brainer but now being two of the buggers your info may be the missing piece.
Cheers

 

Old troubleshooting tip, last thing first. If a change makes it worse, don't go further down the troubleshooting rabbit hole looking for a solution without going back a step first. You'll just get more and more confused as you introduce more problems. I'd swap the MAF's back out and note what the actual codes are. CEL's are a guide to troubleshoot, not necessarily what's actually wrong. From what I've read the XKR's are prone to flow differences causing faults among other things so step cautiously. Hard to assume with out more relevant info.

 

Good to do a "hard reset" after installing a new MAF. Hard reset by either disconnecting battery for about 24+ hrs. or disconnecting battery leads from battery and then connecting the leads together for about 5-10 minutes.
Jaguars are extremely sensitive to air leaks in intake tract around the MAF and forward from the MAF to the motor. MAFs have an 0-ring seal to the intake tract tube. I smear a light coat of silicon gasket sealer on the 0-ring.

 

Big question for me is " what brand is the replacement MAF" ?
I would only stick to Denso original manufacturer

 

It is a remanufactured one from CARDONE

 

Well that explains a lot.

 

How so?

 

Electronics are funny, refurb stuff may pass one set of refurb tests but fail in actual service, kind of like why it was swapped out in the first place. Did you put the original back in place yet?

 

Remanufactured sensors are like retread tires. Sometimes you luck out, other times not so much. If you've gone in and cleared any codes and none have come back since the sensor replacement, and the car still runs rough, then it's the sensor. Verify by reinstalling the old sensor.

This is after the fact, but did you try simply cleaning the bad sensor before you replaced it? Auto parts stores carry MAF cleaner sprays and if you follow the directions on the can, they can fix things sometimes.

 

Also an interesting note. Mass airflow meters are pretty simple devices. They have a sampling passage that contains a thermostat and a heating element up stream next to it with a control circuit. The control circuit reads the amperage load needed by the heating element to maintain the thermostat set point. The more air flow through the meter, the higher the amp load needed to maintain the temp and that amp load reading is sent to the ECU. The newer ones also have a reference thermostat which helps the calibration throughout air temperature variances.

When you clean the MAF meter the goal is to remove build up on the heating element and thermostat, typically fuzzy residue.

 

MAF cleaner spray, as I understand it, is just electrical contact cleaner without a lubricant in it. Save a few more dollars just by getting electrical contact cleaner that doesn't have the lubricant (or states it leaves no residue or is "quick drying" type).

 

I took the new one out and put the old one back in. Went for a good drive and so far no code. I had cleaned the original with MAFS cleaner before but had no luck. Cleaned it again and so far so good. The Cardone MAFS is the second one I tried to put in. The first one was an OEM manufacturer called Bremi (I think). It did not work either but I noticed that the pins were all the same colour vs the stock one that has a different coloured centre pin. So the Cardone is in the process of being return. Will see how my original one performs. I do not get a restricted performance msg vs my 2000 XK8 which did until I change the MAFS and she has been running perfect since. Love both of my cats.

 

Have been chasing the same issue with mine for some time now, and was informed that their was at least two grades of these sensors, W H T F???? This exotic auto shop that i spoke to, only uses Jaguar sensors, as the others are not calibrated as well, and has had a LOT of problems with them. You may also have other issues, intake manifold gaskets are a common issue on these motors. There a set of eight inside the manifold, as well as the two everybody sees.

 

I've seen this with Bosch o2 sensors as well. Ford scripted ones reacted quick to A/F inputs. Bosch scripted ones from the parts store were lazy and tended to read rich over time.

 

Mine just did something rather odd, have not been able to clear the PO101 code, and keep it from coming back on. After almost two hundred miles on theJag sensor, the light went out on it's own When the code reader was hooked back up it read PO101 code pending, that's what happens b4 the check engine light comes on, not after. W T F, i am wondering if it's finally learning the new M A F sensor, it's parameters, and that everything's working like it's supposed to. Sure hope so, i've been chasing this code, off and on for almost a year now.

 

The ECM doesn't learn a new sensor. The sensor has been calibrated to provide either voltage or resistance within a certain range that the ECM is expecting. It either works or it doesn't.