maximum negative !!!! (that can't be good)

Hi all,

Ok... suddenly on the way home from work my 4.6 on gas started to run like it was missing, so switched to petrol... no difference, called at the local parts place on the way and picked some plugs up (ngk bpr 6es), changed them and still no difference. so I rang a pal to pick his brains who said his mate was coming round later who has a computer he could plug in and will ask him to do so, brill !!
anyway he turns up and plugs this expensive looking "snap on" computer in and it came up with.....

P1179 MAXIMUM NEGATIVE AMFR CORRECTION FAULT
and
P1157 OXYGEN SENSOR ENGINE LEAN *codes* BD

I've done some searching and would like to know if I am right by thinking this is ....
1. Air flow meter (p1179)
2. Lambda sensor (p1157)

Any replies will be gratefully received as I am not one of the mechanically minded among us and also pretty skint so could do with not throwing part after part at it !!
Thanks very much in advance.

Might be an idea to post what model and what engine you have.
sorry just the year model as you have a 4.6 as i read in the thred

Oopps sorry,
It's a 96 on a p reg 4.6 hse

Was his Snap-On device just an standard OBD-II reader as the RR uses its own protocols through an OBD connector....if so, it may be worth while finding someone with the full fat RR device like a Nanocom, Faultmate Extreme, Autologic, testbook, et al that are specifically for the RR....

Not sayi g the codes above are wrong, but the RR doesn't use standard OBD-II protocols.

Just been reading the RAVE manuals EOBD codes list and 1179 and 1157 dont appear on the list....

:welcome:,hi i dont know if this will apply to yours but i thimk its worth a try and its at no cost so if it works then great at least your not throwing good money on trying to resolve your problem ...here goes , i have a 2000 v8 4'6 with thor engine 90,000 miles on clock petrol / lpg ,, it is well looked after and serviced regularly .. mine went on the blink ,i had it serviced as usual 1st the petrol side then the day after the gas side after about 12 weeks it started running like a singer sewing machine either on gas or petrol , checked all usual stuff , plenty of gas plenty of petrol ,plugs and leads all ok filters all ok ,sat and thought about it and read up on rave about the maf sensor ,,everyones opion said replace it CANT BE REPAIRED OR CLEANED ?????? BUT AFTER MORE THOUGHT i took it off had a good look at it and thought ill give it a try on stripping it down and cleaning the two thin strips of wire and everything else and if it doesnt work then buy a new one ,,so i borrowed the wifes nail polish remover and went to work with a cuople of ear buds and cleaned the wires i.e. the sensors and cleaned all inside etc etc ,left it outside for a couple of hours so the liquid would evaporate , refitted it and it started perfect changed over to gas and that was perfect ,ran it up the road for a while and back home stil perfect and has been for last six months ,, problem dirty maf sensor cured at no cost just a bit of time !!!!!!!! so try it first and forget what the book and main dealers say cos in my case perserverance steps in !!!!!!! hope it works for you kind regards mozz ,,,,moral of the story is always start at the cheap solution rather than blindly throwing money at a unknown reason why its doing what it does

cheers everyone,

I tried the cleaning of the air flow meter, first with electrical contact cleaner, I was then told I should be using carb cleaner, so I did it again with some of that.
unfortunately none of that worked.
so as much as it hurts me, I'm gonna have to take it to a specialist and pay the £60 they want just to plug it in (is that the going rate ?),
I was going to take it to the main stealer but every time I call them for a quote on parts prices or for some information, as soon as I mention a p38 they talk to me like I'm wasting their time ! so they can NAFF OFF !!

I'll update when I know more just in case this happens to anyone else,
Thanks again.

Not sure if this helps but it helped me, I had an intermittent fault on my 4.6 hse (97p) and I changed plugs. leads and even teh washer jet pipes which were piddling over the Ht leads at one point.

It ended up being a coil for cyls 1 and 6 (same dude), I sussed it after help on here and after buying two sets of those clever transparent red spark plug connector extensions from Halfords, you can see the spark basically, I could see 1 and 6 were not firing. Bought coil pack from Britpart (think £150) and perfect.

I have three used but okay coils if anyone wants to try one.

Nige