DPF Filter and Lamnbda Sensor on A4 170 Tdi 57 Plate.
Discussion
Hello I have an Audi 170 Tdi on a 57 plate.
Been having problems with my egr valve for several months but car was running fine apart from engine management light on. Then DPF light came on along with the coil light and car went into limp mode.
Took it to local in dependant and asked them to sort out DPF with a forced regeneration if required. ( had one done couple of years). Told them to leave erg alone. Anyhow they rang me next day to say car was sorted and DPF was completely blocked but all cleaned out. Charged me £190.00 for the privilege..
Next day engine management light returned followed by DPF light and coil light and into limp mode again. Returned vehicle and called me next day to say needed new DPF and EGR valve. Was going to cost over £1000 but cheaper option was to fit new EGR valve and cut out and remove DPF and re map it and at same time increase power etc.
Reluctantly agreed to have this done. The called to say car was ready charged me another £750.00. I argued that they shouldn't expect me to pay the £190.00 originally as it hadn't worked. Reluctantly they. agreed.
Paid the bill drove off and after a few miles hey presto engine management light came on. Took car back in next day and I am now told the Lambda sensor on the exhaust is faulty..
Not yet picked car up I know damn well they will want paying for it. My question is after looking on this and other forums it has been mentioned that 99/100 times although fault codes saying DPF filter it's the pressure sensor (Lambda) on the exhaust that at fault.
If so have they removed the DPF unnecessarily when in fact after they had originally cleaned it , it would have been ok had they picked up on the pressure sensor as they now have. I just feel they are going to expect me to pay for it all..
Been having problems with my egr valve for several months but car was running fine apart from engine management light on. Then DPF light came on along with the coil light and car went into limp mode.
Took it to local in dependant and asked them to sort out DPF with a forced regeneration if required. ( had one done couple of years). Told them to leave erg alone. Anyhow they rang me next day to say car was sorted and DPF was completely blocked but all cleaned out. Charged me £190.00 for the privilege..
Next day engine management light returned followed by DPF light and coil light and into limp mode again. Returned vehicle and called me next day to say needed new DPF and EGR valve. Was going to cost over £1000 but cheaper option was to fit new EGR valve and cut out and remove DPF and re map it and at same time increase power etc.
Reluctantly agreed to have this done. The called to say car was ready charged me another £750.00. I argued that they shouldn't expect me to pay the £190.00 originally as it hadn't worked. Reluctantly they. agreed.
Paid the bill drove off and after a few miles hey presto engine management light came on. Took car back in next day and I am now told the Lambda sensor on the exhaust is faulty..
Not yet picked car up I know damn well they will want paying for it. My question is after looking on this and other forums it has been mentioned that 99/100 times although fault codes saying DPF filter it's the pressure sensor (Lambda) on the exhaust that at fault.
If so have they removed the DPF unnecessarily when in fact after they had originally cleaned it , it would have been ok had they picked up on the pressure sensor as they now have. I just feel they are going to expect me to pay for it all..
O2 (lambda) sensors and differential pressure sensors are two different things. O2 sensors on a diesel (where fitted) are generally used for fuel injection quantities and monitoring EGR. DPF sensors (G450-yours is now redundant) monitored DPF soot content for regeneration. The O2 sensor may be clogged up due to the excessive soot content in the exhaust prior to the EGR replacement. The faulty EGR may well have caused all the issues. I hope you get it sorted.
Been there, done that!!
I've got a Golf GT 2.0 170 and had all the same problems. The pressure sensors are a particular pain - there are apparently 3 of them - and they're >£100 each.
The DPF removal is a boon in some ways - it eliminates the soot build-up issue and the associated re-map changes the nature of the car completely. The only thing I'd say is, according to the most recent rules, you may find that the DPF delete is an automatic fail come MOT time. I would be inclined to get the garage to confirm an MOT pass - and remember where they took it!!
I've got a Golf GT 2.0 170 and had all the same problems. The pressure sensors are a particular pain - there are apparently 3 of them - and they're >£100 each.
The DPF removal is a boon in some ways - it eliminates the soot build-up issue and the associated re-map changes the nature of the car completely. The only thing I'd say is, according to the most recent rules, you may find that the DPF delete is an automatic fail come MOT time. I would be inclined to get the garage to confirm an MOT pass - and remember where they took it!!
DPF removal is a fail if they can see its been removed. I've recently had mine done and due to the covers that are fitted its not possible to see where the dpf was cut open and re-welded.
I've not had any troubles with the dpf really but since the car is coming up for 80k its only a matter of time but had I known how much better the car would drive I would have done it ages ago
I've not had any troubles with the dpf really but since the car is coming up for 80k its only a matter of time but had I known how much better the car would drive I would have done it ages ago
On PD 170s all of the components you mention can (and do) fail.
The process of guided fault finding does not always lead to an individual component or system; very often it requires that a component is cleaned/checked/replaced before suggesting further diagnostic tasks. This process is determined by VAG and is the 'correct' way of doing it.
Your garage may have been wrong, but just as likely they were right. It isn't an exact science, sadly.
The process of guided fault finding does not always lead to an individual component or system; very often it requires that a component is cleaned/checked/replaced before suggesting further diagnostic tasks. This process is determined by VAG and is the 'correct' way of doing it.
Your garage may have been wrong, but just as likely they were right. It isn't an exact science, sadly.
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