Fecking piece of sh!t!!

[S4_dan]

Fitted two new lambda sensors yesterday. Had to remove the cats and replace the sensors.

Car is now doing LESS mpg and runs like a bag of sh!t! Idle is fine, but driving with the revs under 2.5k rpm, it judders and feel like its misfiring. MPG is down 25. The old sensors were at least getting me 30/31!! Overall, the power is down massively. Tried flooring it and was shocked!

Exhaust gasses dont smell rich or eggy. I do however, has a blow from where the cat mates with the manifold. I'm getting two new gaskets today and will fit them tomorrow.

How come two new lambdas have made the car worse....alot worse! Horrible drive home last night from work. Didn't think I was going to make it home!!

 

[warren_S5]

Maybe car has got used to running with old settings and needs to adapt. Have you had her on VCDS?

If the exhaust is blowing it's never going to feel 100%, so get that sorted then re-evaulate your issues.

 

[S4_dan]

Yeah I scanned first thing this morning. The TB fault has been present for a while without any known problems to car. I'm looking into getting a replacement.

However, I didn't scan the car before swapping sensors over, but last time i did scan there was no fault codes relating to the lambdas. I've just nipped up the exhaust bit tighter and the leak has almost stopped. New gaskets will cure that.

Here are codes:


VCDS-Lite Version: Release 1.0
Wednesday, 07 September 2011, 07:05:17:0
Control Module Part Number: 4D0 907 551 F
Component and/or Version: 2.8L V6/5V MOTR HS D03
Software Coding: 04201
Work Shop Code: WSC 00020
3 Faults Found:
17967 - Throttle Body (J338): Fault in basic settings
P1559 -- 35-00 - -
16519 - Oxygen (Lambda) Sensor B1 S1; Heating Circuit: Malfunction
P0135 -- 35-10 - - - Intermittent
16551 - Oxygen (Lambda) Sensor B2 S3; Heating Circuit: Malfunction
P0167 -- 35-10 - - - Intermittent


I've cleared said code and will see what the journey to work is like. The car drove fine to work yesterday, acheiving 30.3mpg. I change sensors over at work and had the horrendous journey home at 25mpg.

 

[aragorn]

A leak before the lambda will typically cause the car to run rich.

Lambda detects oxygen, and a leak means more oxygen is present, which in turn means the sensor reports a lean mixture and the ECU cranks up the fuelling.

You can look at the long term trims in vagcom to see if this is happening.

 

[S4_dan]

Picked up two new manifold to cat gaskets, 2 bottles of G12 plus plus & 5 litres of Quantum oil. All for a whopping £30

Car is running better. Still got soome issues at low revs in high gears (3rd and above) with juddering. Not becase the revs are too low! Occurs between 1.5 and 2k rpm.

Achieving a respectable 34.2mpg at the moment. Hopefully once the exhaust blow is sorted it may increase a little more!