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 mass airflow sensor's readings aren't adding up — the ECU is comparing what the MAF says against what the engine's actually doing, and the numbers don't square. The cheerful news is that the most common cause is simply a dirty sensor element, fixed with a £6 can of MAF cleaner. Next up: air leaks between the MAF and the engine (air sneaking in that the sensor never counted), or a clogged, oily air filter fouling the airflow. A genuinely dead MAF is the last resort, and even then it's not a bank-breaker."
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 mass airflow sensor's readings aren't adding up — the ECU is comparing what the MAF says against what the engine's actually doing, and the numbers don't square. The cheerful news is that the most common cause is simply a dirty sensor element, fixed with a £6 can of MAF cleaner. Next up: air leaks between the MAF and the engine (air sneaking in that the sensor never counted), or a clogged, oily air filter fouling the airflow. A genuinely dead MAF is the last resort, and even then it's not a bank-breaker.
Usually yes. The ECU falls back on its other sensors when it distrusts the MAF, so the car keeps running — often with slightly lumpy idle, hesitation or worse fuel economy. It won't strand you as a rule, but don't leave it for months; bad fuelling is bad for the cat.
Genuinely one of the cheapest codes going if it's dirt: a can of MAF cleaner is about £6-10 and it's a five-minute job. A new sensor runs roughly £40-150 depending on the car (stick to a reputable brand — cheap clones cause more grief than they solve), plus minimal fitting.
Not with the engine light on — since 2018 an illuminated engine management light is a straight MOT fail in the UK. Clean the sensor or fix the leak, clear the code, and make sure the light stays off before the test.
Free app. Plug in, and get every code in plain English, plus the connections you'd never spot.