First of all... As a New (used) jag owner, I want to thank you all for the great advice and expertise that I have found on this site..


I have a 2003 X-Type, 2.5 L AWD with 91 k on the odometer that I just recently purchased.... about a month.


My CEL came and on last week and I found the code resources helpful on this forum.


The codes are as follows
P0171- Combustion too lean Bank 1
P0174- Combustion too lean Bank 2
P0430- Catalytic converter system efficiency Below Threshold- Bank 2


I have replaced the PCV valve and checked all the appropriate hoses for vacuum leaks.


Could a defective fuel filter cause these issues?


Any advice is greatly appreciated!!


Jaggin in Colorado


BJ

 

Inspect all hoses and connections, such as the one to the brake booster, for leaks. If you cannot locate leaks, it may be best to have a smoke test performed by a reputable shop.

Misfires due to lean conditions can damage the catalytic converter(s). Under no circumstances, operate the vehicle in conditions that cause the MIL to flash as catalyst damage is occurring. In my experience, P0430 could only be resolved by replacing the Bank2 catalytic converter, but first any misfires must be found and corrected.

 

Not what I wanted to hear.... but many thanks

 

+1 on NBCat recommendations. You have a vacuum leak and it needs to be resolved quickly. To answer your question about fuel filter, it won't hurt to change it but a clogged filter would give you a P0301 thru P0306 misfire code.
The things to check since you have changed the PVC Hose and the Brake Booster line would be the following:
1. The fitting where the brake booster line enters the manifold. There is a locking fitting with and O-ring.
2. The fitting where the intake air resonator is attached to the rubber boot downstream of the MAF sensor.
3. The vacuum line downstream of the intake air resonator into the rubber boot downstream of the MAF sensor.
4. The IMT fittings at the end of the intake manifold on the passenger side.
5. The upper and lower intake manifold gaskets.
Starting the engine while it is cool, you can spray carb cleaner around the fittings and look for an engine reaction. You must be careful not to spray the hot exhaust. Any reaction to the spray would indicate a vacuum leak.

 

Thanks for the great advice!