OBDII Code # P1178

[El_Cid_2000]

First off, I've tried to search and I'm not getting any results for this.

The code from http://www.troublecodes.net/landrvr/ is "Maximum Negative AMFR Correction Fault" and from AutoZone where they reset my C.E.L. is "manufacturer control fuel air metering."

This code has popped up three times since last Thursday. The first time it happened it had two codes one was "P1178 Maximum Positive AMFR Correction Fault" and the ?P1179". It has happened on the highway at 65+ mph, city driving at 30-40mph and about three feet out of my driveway at about 5mph. I have not noticed any power loss, hesitation, loss of gas mileage etc. This has started after I got the Rover back from the dealer to diagnose this http://www.discoweb.org/forums/showthread.php?t=1693, as it turns out it was the camshaft sensor going bad. Replaced that and all was right in the world for a couple of days.

I did pull the air flow meter hose and clean out a tiny amount of dust. You think the sensor is too dirty or going bad? From what any of you have experienced with this or something close to it; am I hurting anything by driving it? I?d LIKE to get this straightened out before I head up to MAR this weekend or I won?t be going.

Any ideas?

Thanks,
Michael

 

[RoverChic]

Same code here. Search the archives. Look for a post by Jaime Crusellas. I believe that I cleaned my MAFS (very carefully Sergei)..Cleared the code and it was gone (never to be seen again). I believe that Jaime found it to be his fuel filter. Not for sure though. I also changed the 02 sensors upstream.

I believe the post in the archives actually reads P#1179. Good Luck. Melissa N
1998 D1
Here I found this also for you: Its from Walter aka RoverHound (i.e. cleaning the MAFS)

Electronic degreasers/contact cleaners will NOT leave a residue or harm coatings. That's why I said Electronic degreasers/contact cleaner. As stated before, CRC available at Lowes is good for this application.
Just make sure the cleaner IS for electronics. Let the MAF throughly dry out before installing and starting.
Electronic degreasers/contact cleaners are very fast drying and do not conduct electricty

 

[RoverChic]

Bingo found it::: Damn my memory is GOOODDDDDDD!!
http://www.discoweb.org/41704archive/DiscusArchive/messages/2/46835.html#

Hope this helps bro!!!

 

[BradN]

according to my OBD2 manual. the cose P1179 is listed under the oxygen sensor and fuel system section of the manual. It lists the fault code as "long Term fuel trim too rich, banks 1 & 2 (AMFR). while P1178 is "long Term fuel trim too lean, banks 1 & 2 (AMFR). I do not know what "AMFR" stands for. I am not sure the mass air flow sensor is the root of the your problem. I can email you the section out of my manual if you want. just let me know

 

[andrewv]

MAFS. Electrical contact cleaner may work, and it's certainly worth a shot.

 

[El_Cid_2000]

RC,

Thanks for that thread it was helpful. I'll get a fuel filter pronto and change it (couldn't hurt anything anyway). How can I test my o2 sensors to see if they are out of range? Or is that a shop job?

Once again thanks for that link and your first post. I ran to Lowes at 8:54 and got a can of the CRC and cleaned the MAF and it's connector by flashlight. Hope it helped. Will report back tomorrow.

BradN,

Thanks for the offer of the codes but I just won an OBCII tester on eBay and it comes with the list that I assume is the same as yours. There is also a good list at:
http://www.troublecodes.net/landrvr/



Thanks,
Michael

 

[RoverChic]

No worries Michael! Hopefully that cleaning will resolve the issue. Yes you can test the 02 sensors. I would put $$ on the upstream ones, as the ones downstream really only monitor the state of the catalytic converters. How are the cats? Any rattling (marbles in a can noise) and/or the such? I will have to search for the specs on the 02 sensors (i.e. verifying that they are *ok*). I do have them around here somewhere. You will need an OHMS reader for that though. Melissa N

 

[BradN]

El Cid

The code book I have is the official Land Rover OBD2 Trouble shooting manual that I downloaded from theLand Rover techincal infor site. It covers Discover, Range Rover and Defender up to 1999. I am not saying the one you have is wrong or any thing like that. I just wanted to let you know the LR manual list the fault code different from what other sources are listing. Mass air flow sensors cost a crap load $$$ compared to O2 sensors. It has been my expereice that a faulty O2 sensor can cause other faults to occur. Just my 2 cents. I hope every thing works out for you.

Brad
96D1 with 105k