This is a recent message I received from a customer regarding an EGR delete carried out on his vehicle.
“I have a VW T5.1 and the coil light illuminated a couple of months ago. I took it to a garage who diagnosed a faulty EGR valve and Cooler. I took advice from friends and family to have the EGR deleted at a cost of £130 rather than the quoted £1100 to replace the EGR valve and cooler.
Within 100 miles, the DPF regen light came on, followed by limp mode. I took it back to the remapping company who forced the regen and said it was fine.
I drove up to Inverness (400 miles) where the DPF regen light came on again, and then the van went into limp mode. A remapping garage in Inverness forced it into regen mode again and I managed to get home before the DPF came on again. I took the van to a specialist DPF cleaner company who stated that DPF was full of ash and soot and cleaned it out. I drove the van for a week (around 200 miles) before the DPF regen light came on again.
Before I spend a lot of money at the VW garage, do you have any thoughts/advice?”
Unfortunately, this is not uncommon. Whoever worked on this car failed to investigate the root cause of the problem, and forcing the DPF to regen every few hundred miles is only addressing the symptoms.
The engine ECU will not permit a passive DPF regeneration if a problem is detected. This would include any anomaly it detects with the EGR function. If the EGR delete has not been coded correctly, then the DFF won’t be able to regenerate on its own. Writing the warning light/code out of the software is not always sufficient as the ECU needs to “see” via various sensor outputs, that the EGR is operating correctly. If the DPF problem started after the EGR deletion, then that should be investigated first.
It is also worth noting that it is an offense to use a vehicle with any part of the emission control system modified to alter the emissions standards it was originally designed to meet. I hope the customer was advised of this.
