I've had problems with recurring P0172 code (too rich Bank1) with accompanying Restricted Performance on my
2003 X308 N/A North American model.
My local garage (not specialist) diagnosed that it was the MAF and replaced it with an OEM MAF. This cleared it
up for about a month but it started to recurr and once was very difficult to start with the symptoms of a flooded engine.
I got it going quite quickly by opening the throttle wide and it started after stumbling and clouds of dark smoke. So I assumed
a leaking injector and installed a set of remanufactured injectors from a well-known shop. Now I have it all back together
and it runs fine but I can't get it out of Restricted Performance. I plugged in my iCarsoft and there are no codes (the P0172 code
is now gone).
Before, when there was a code, I could clear it and the Restricted Performance would be gone.
The fuel pump, filter, spark plugs, air filter, fuel pressure regulator and timing chain set are all new within the last 5000 miles.
The car runs very well except for this one problem.
Any ideas?

Cheers,
Andy Webb

 

Perhaps removing the negative terminal on the battery and touching the two cables together for about 30 seconds and re-applying the battery cable. Before you start the car, turn the key to the run position, (before the Start position), hold the accelerator to the floor for about 5-10 seconds. Let it up slowly and wait a few seconds before starting the car. No guarantees but it's worth a shot.

These cars are finnicky; especially the P0172 codes. I went through a lot of things before I go it to clear on my car. Finally changed an O2 sensor and it seems to have settled it down now.

 

Thanks, David, I'll give that a try. I'll check battery voltage, too. I use a Noco Genius battery charger
but I think my battery is about 6 years old now and these cars are so fussy aboutbattery voltage.
Cheers,
Andy

 

Update: Your hard reset plus the throttle pedal tip worked! No codes and no Restricted Performance now. I took a 20 km test drive and it is still
good. Plus the set of remanufactured fuel injectors seem to make the car peppier.
Thanks again,
Andy

 

Sorry to say many codes need 2 trips (warm ups) to flag but here's hoping nothing does.

Also, many codes can't flag unless most/all OBD monitors are set (aka complete aka ready). Check via OBD but do not clear codes as that unsets all monitors as well.

 

X308R myself. To me, there's been some inconsistent recommendation online for the "Restricted Performance" issue, it could be any thing and the worse is having to replace with new parts to find out if it works. I watched the Youtube video Asian fellow with the Red XJR is Virginia plates, and I used the MAF cleaners to clean my MAF. I also got new NGK #48272 branded ignition coil from RockAuto, to replace old 70k parts. Since then, 2 years ago, that kind of made the "Too Rich" bank issue go away for me luckily and I do not recall another Restricted Performance. I stil clean out the MAF annually.

As a project, I still need to get the ABS module fixed and a gasket seal, as blue exhaust is coming out. These are predictable for me and I know my Jag specialist can do it, with enough money on the side. In the back of my mind, until these things are done, I can expect the CES.
When I try to go for emission check every 2 years, it's a hit or miss if the CES will come on, with every thing being the same. If it does not, I pass the check.