I have a 99 XK8 and my engine light came on today.I plugged in a OBD2 reader and it came up with 'system too lean,bank 1' code P0171 & code P1111 that gave no description. Anyone maybe know what this is? Is there an obvious answer that I don't know about?

 

Isnt the P1111 code a factory thing - showing that system checks have not been completed? Havent come across P0171, sorry!

 

More here.

 

Welcome to the forum debibbean,

I've deleted your duplicate post from Jaguar Forums Advice / Feedback & Suggestion Center section.

You will always see on of these codes:

P1000 : the on-board diagnostic tests have not been completed
P1111 : all on-board diagnostic tests have been completed

You have correctly identified P0171. The possible causes are shown below in the right hand column:


When you get a minute, please follow this link New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum to the New Member Area - Intro a MUST section and post some info about yourself and your vehicle for all members to see. In return you'll get a proper welcome and some useful advice about posting to the forum.

Graham

 

One common cause is a leak in the intake tube. The accordion section near the air filter is especially prone to cracking after years of exposure to engine heat.

 

I was getting a P0171 every once in a while when I bought the car last year (103K mi). All the other recommended inspections checked out good, so I changed the fuel filter about 10K miles ago and haven't had that code appear since. (124K mi now).

I did cut the filter open and it pretty dirty in there.

"Always fix the cheapest option first - ALWAYS!"

 

In my case I was getting P0171 and P0174. It turned out my MAFS was dirty and the accordion section of the intake tube had many slits (probably why the MAFS was dirty). I cleaned the sensor, mended the intake tube until a new one arrived and I haven't had a problem since. It was also coupled with an intermittent restricted performance light. I haven't had the codes, misfires, or a check engine light ever since. The car even feels more responsive.

I suggest you check everything related to intake. The filter, make sure it's clean, if not you can buy a purolator for about $30, the intake pipe (about $50 at Gaudin). IF you have to clean the MAFS be careful. They sell a special cleaning agent for it. Don't use brake fluid, or any kind of oil. On the other hand, I found that q-tips, cotton *****, and a very small soft bristle brush did the trick, without the need of any chemicals.

If your problem isn't caused by the intake system, nothing I have said is of any help, but, it doesn't hurt to check, replace and clean that stuff.

 

Hi...thanks for all the replies. Everyone was pretty much right on both codes. I have been running it pretty low on gas lately (more so than normal) so I put some Chevron Techron fuel cleaner in it and within an hour the check engine light went off. Thats like a miracle. Lesson learned. No more running it low on gas. Thank u.

 

Thanks for posting the result. Good to hear you're running CEL free again.

I've added 'RESOLVED' to your thread title to help others looking for information on the same issue in future.

Graham