Ask Honest John

Most recently answered dpf questions
I have a 2012 Hyundai ix35 1.7 diesel, which is under a finance agreement. The vehicle frequently goes into limp mode, exclusively under acceleration such as overtaking or joining the motorway. The dash...
Are there any diesel engines where the regen fuel is not injected directly into the engine on the exhaust stroke? To my mind a DPF should ideally be as close as possible to the exhaust manifold and have...
I am thinking of purchasing a five year old Mazda 6 2.2 diesel. I've identified a few for £7000 that have around 70,000 miles on the clock. Would you count these cars as good buys? I'm a little bit confused...
I have a commute of eight miles a day, five days a week. Over the course of a year, I cover 8000 miles and I rarely do journeys of more than 10 miles. Will a new Nissan Juke 1.5 diesel be suitable for...
My Vauxhall Insignia emission filter light is constantly flashing. At first the light came on with 'code 55'. I researched this and did as advised by driving over 2000 revs to clear it. The code 55 disappeared...
My 2010 BMW 3 Series diesel has done just over 30,000 miles and the engine function light (Orange) is displayed intermittently. My Independent Garage has run a full diagnostic test and is not really sure...
I have an intermittent fault with my Audi A6. The Emission Control light comes on and goes off randomly. It all started in October where I had to do a lot of short journeys. But most recently the light...
I've removed the DPF and EGR from my Vauxhall Signum, due to constant engine problems. Is the car legal if the model is pre-2008?
I have a 2011 Peugeot Partner Teepee 1600 diesel. The DPF was recently changed (108,000 miles) but the warning light has just come on saying chance of blocked filter. I have just driven the car for...
I own a Vauxhall Corsavan 1.3 CDTI, which has suffered its second DPF failure in 12 months. Vauxhall informed me that the first failure was down to me driving it wrongly. I had argued but was unsuccessful...