AFR Bad on 456

[scotty1]

Hi All,

Some advice if anyone has experienced the below

Symptoms:

1)Passenger side exhaust note different to drivers side
2)ECU software readings all within the tolerances specified in the software, read me files
3)Fault code screen shows AFR bad on cylinders 456, when I clear this it returns immediately with slight revs

I have checked plugs & leads, can anyone recommend anything else to check ?? Its worth mentioning that the car drives and responds ok

thanks
Scott

[hollowpockets]

iv noticed my passenger side exhaust seems to have slightly more pressure and barble to it than drivers side but its always been like that and never had any error codes idicating problems.

[scotty1]

hollowpockets said:

iv noticed my passenger side exhaust seems to have slightly more pressure and barble to it than drivers side but its always been like that and never had any error codes idicating problems.

yes that's exactly the same as mine, maybe it's nothing to worry about, as I said the car drives fine so who knows...

[Peppe]

Hi Scotty !

If you look at the adaptive maps, what do they show ? They should be equal on both engine banks.
Are the throttle pot readings equal on both banks and the readings steady from idle to full throttle ?

Otherwise i think your problem has to do with the throttles not being balanced. See topic, page 2:

www.pistonheads.co.uk/gassing/topic.asp?p=1&f=152&t=362929&h=0

What software version are you using? If you have the old (blue cerb version) you wan´t be able to reset the throttle pots. It might help just doing that and a reset of adaptive values.

Peppe

[trackcar]

the throttle pots rest themselves every time you switch the ignition on on sp6 cars so no worry on that score. if the adaptives are out then there's a reason, just resetting them cures the symptom for a short time till they re-learn the old bad values again ...

[scotty1]

To be honest all the readings are within the tolerences they should be.....the throttle pots are more or less spot on...

The adaptive map readings do vary but normally by about -17, the readme files suggest that as long as these readings do not exceed +- 20 there isn't a problem...

I know I have a Saggy chip and Nov 06 Ecu due to a rebuild at the factory in Nov 06 could this be the wrong chip bearing in mind its a 3.6l not 4.0l..

Can anyone tell me if cylinders 123 service one exhaust manifold and 456 another...what I mean is the two manifolds roll into one pipe then separate again into two. I am trying to figure out if the different engine note from the passenger side exhaust is from bank 456..where the bad AFR is being reported

hope that makes some sense??

cheers for replys btw

Ps I have the new software (yellow cerb graphic)

Edited by scotty1 on Monday 2nd April 20:54

[Peppe]

Hi Scotty!

On my Cerbera the exhaust is separated from front to back.

Are both adaptive values, bank123 and bank456 at the same level?

Peppe

[scotty1]

Peppe said:

Hi Scotty!

On my Cerbera the exhaust is separated from front to back.

Are both adaptive values, bank123 and bank456 at the same level?

Peppe

Hi Peppe,

I will need to double check this but from memory they are different but no greater than +/- 20..

I will double check this tonight