Filled up with gas yesterday and within 1 mile had the Restricted Performance and check engine light illuminated. Is the fact that I topped the fuel tank up likely to trigger these rich codes or do I need to dig deeper?Any help appreciated!

 

It shouldn't be related to how full you filled it. Go digging...

 

I suspected that would be the case - I just thought I'd seen a warning from one of the techs on here that topping it up too much could affect the evap system. It's also started throwing engine failsafe/transmission fault/trac control - no P codes other than the 0172/5 - although my reader can't do C codes. Is it likely to be one cause for all this or not? Battery is good and alternator is putting out 14.1v at idle.

 

I changed the air filter, cleaned the MAF(which was new 2 years ago),cleaned all TB plugs and put injector cleaner into the gas. Hard reset then took it for a 60 mile run - all smooth and no CEL. Then last night restricted performance and CEL. I've checked the fuel rail pressure - holds 40psi for over an hour after shutdown. Only code showing now is P0172 and freeze frame data shows:


Closed Loop
Coolant 190.4F
Fuel trims
B1LT -4.7
B2LT -0.8


B1ST -22.7
B2ST - 21.9
Vehicle speed 48.5mph
MAF 29.76gms/sec
Calc.load 43.5%
Engine rpm 1672
Intake air temp 100.4F
TPS 9.8%


Anybody know whether these figures point to a particular component.


Thanks!

 

The P0172 & b175 are rich fuel codes and could be caused by many things. The fact that it is universal to both sides 172 & 175 would tell me it involves the air/fuel delivery so I would check the air intake for blockage or restrictions. I would also check all the throttle body plugs connections to be clean and tight and I would also add the MAFS to the list of plugs to check.

I have heard rumors of the over filling the tank but never experienced it. Also check your gas cap being installed properly.

This is a test for the MAFS that you may want to perform.

Link JagRepair.com - Jaguar Repair Information Resource

Link to Codes http://www.jagrepair.com/images/Auto...J27%201999.pdf

 

Thanks Gus - I'll check the MAF figures against your chart. I have removed, cleaned and refitted all throttle body and MAF sensor plugs before the 60m test drive. Whatever the eventual solution I'll post for the benefit of anyone else with these codes.