Darren Darling, Head of Training and Technical Support at the DPF Doctor Network, talks to PMM about everything from how he got into the aftermarket to his partnership with JLM.
On starting out
A lot of technicians talk about going into the industry because of their dad or because they follow racing and grew up around cars, but I just wanted a real job where I could get my hands dirty. So, I left school and my dad kicked me out the door one morning and said not to come back unless I got a job – and that was pretty much it, I came back with a job in a garage!
On beginning DPF work
I worked on trucks to begin with and so naturally saw a lot of diesel engines and the first DPF started coming out on vehicles in the late 90s. I’ve been self-employed for probably around 18 years now, initially specialising in diagnostics work and around seven or eight years ago this took me on a natural progression to specialise in DPF work. A lot of people were asking for it and were having repetitive problems, making it clear to us there was a fundamental flaw in the process – so we honed our skills in it. We never set out to do the training and everything that came along with it, just to be a local, good quality DPF repair specialist.
On specialising
It’s important to emphasise that we didn’t immediately drop all other work we do, we just made a conscious step to be truly specialist and know the job inside out – this meant cutting out distractions like keeping up to date with other technology. There has to be a transition and once you start getting a good at what you do and the jobs start queuing up, that’s when you have to stop other work because there’s just not time for it.
On becoming the DPF Doctor Network
Originally, the DPF doctor was just a tagline for me and Callum, my right-hand man, but the network came about when the phone starting ringing from workshops who needed help. From this, and with help from my wife, we added some structure where training and help was offered alongside a forum. The network itself was kind of an accident but now we work with other workshop to provide full access to our help, training and support. If they’re stuck on a job there are resources available.
On forced regenerations
One big thing for us is that we don’t carry out forced regenerations, full stop. There are two jobs in our workshop today where the DPFs are beyond repair – that’s generally down to a use of additives reset when it’s not safe to do so. This isn’t to criticise or patronise someone for doing it because they haven’t been educated it’s just to say that if you’re not sure it’s safe to do so, please don’t do it. It’s important to brush up on your knowledge and practise ongoing training.
On working with JLM
Working with JLM came about because I was a customer with very high standards – when I’m using a product the cost doesn’t matter, it’s all about quality. It’s really important when working with DPFs that the products are working with us and that they clean at safe temperatures. I worked my way through various products and found that JLM delivers, but the company itself is also small enough to listen. Now, I’m a global brand ambassador. We have a few products in the range and we normally have an annual sound board and wish lists so we’re kind of the guys on the ground. They listen to us, they’ll go and do the R&D and then we do the real world testing, which is brilliant.
On joining the DPF Doctor Network
To join, send an enquiry form to and after that I just like to have a chat to each person as it’s important to me that they have the right attitude and want to improve themselves. It’s not so much needing to be an expert but it’s important that if a customer goes into a workshop that’s listed on our website that they are greeted by a friendly face and that the car’s fixed properly.
