Pick a colour. The page changes, like the app does.
Officially? A wall of jargon. To most people? Absolutely nothing. That's exactly why we built the app.
Plug into any code reader and you'll get the same line every other app shows you. Technically correct. Practically useless.
"The EGR system recirculates a bit of exhaust back into the intake to cut emissions. Right now it isn't flowing as much as the ECU asks for. On the vast majority of cars, especially diesels, the story is carbon: soot builds up and gums the EGR valve or blocks its passages until the valve can't open properly or the gas can't get through. Diesels that do lots of short, town journeys are the classic victims. A good clean often fixes it; a new valve is the step after that. Vacuum-operated setups (older petrols) add a possible split vacuum hose to the cheap list."
Worth checking in roughly this order. Don't jump straight to the expensive fix:
The code itself is a snapshot. The fault sets after the car's watched the numbers over a whole drive cycle. Here's what's worth keeping an eye on:
Live simulation on the readings our free demo drive supports. This is how the app’s dials move.
Codes rarely tell the whole story. The clever part is reading them together, and against your exact car. Here's the kind of thing it catches:
The EGR system recirculates a bit of exhaust back into the intake to cut emissions. Right now it isn't flowing as much as the ECU asks for. On the vast majority of cars, especially diesels, the story is carbon: soot builds up and gums the EGR valve or blocks its passages until the valve can't open properly or the gas can't get through. Diesels that do lots of short, town journeys are the classic victims. A good clean often fixes it; a new valve is the step after that. Vacuum-operated setups (older petrols) add a possible split vacuum hose to the cheap list.
It depends on the fuel and on what comes with it. On a petrol it's usually an emissions fault, and the car drives as normal. Many diesels cut power or go into limp mode with this fault. If yours does, stay off fast roads and get it checked. Either way, don't park it for months.
Day to day you may notice nothing, or perhaps slightly lumpy running and, on diesels, a bit more smoke. Many diesels cut power or go into limp mode with this fault. If yours does, stay off fast roads and get it checked. On modern diesels a poorly EGR system can also knock on into DPF problems, which are expensive, so don't park the issue for months.
A DIY clean costs a tin of carb cleaner and an afternoon. A garage clean is modest labour. A new EGR valve is where it stings: roughly £80-250 for the part depending on the car, plus fitting. Some diesels bury them awkwardly. Cleaning first is almost always worth the try.
A lit engine management light is an MOT fail item on any reasonably modern car (petrols from 2003, diesels from 2008), so fix the fault first. On diesels a poor EGR can also raise smoke levels, which the MOT does measure. And to be clear: deleting or blanking the EGR to 'fix' it is illegal for road use in the UK and an MOT fail in itself. Clean or replace it properly.
Free app. Plug in, and get every code in plain English, plus the connections you'd never spot.