MAF signal drops in and out — usually a loose connector or a MAF failing on the way out.
P0104 — also written PO1O4, P 0104, 0104 — is the OBD-II code for mass air flow (maf) circuit intermittent. Same code, same fix: this page covers every spelling of it.
This code means the ECU is losing its 'eyes' for a split second because the MAF signal is flickering, usually on common UK diesels like the Ford TDCI or VW TDI.
P0104 is a sensors fault code, typically costing £25–£320 to put right in a UK garage.
What P0104 actually feels like to drive
- The car 'hiccups' or stutters for a split second while cruising at motorway speeds.
- Engine suddenly goes into Limp Mode but clears itself after you cycle the ignition.
- Rough idling that comes and goes, especially when you’re sitting at traffic lights.
- A sudden puff of black smoke from the exhaust when the signal drops and the ECU over-fuels.
- The car feels 'flat' one minute, then pulls like a train the next.
What causes P0104?
- Loose MAF plug
- Broken MAF sensor element
- Wiring rubbed through on a heat shield
- Split intake boot pulling unmetered air
UK vehicles that throw P0104 most often
- Ford Focus 1.6 TDCi (DV6) 2011-2015 - Common wiring loom rub-throughs.
- Vauxhall Insignia 2.0 CDTi (A20DTH) 2008-2017 - Plug tension issues.
- Volkswagen Golf Mk6 1.6/2.0 TDi 2008-2013 - Sensor element failure.
- Nissan Qashqai 1.5 dCi (K9K) 2007-2013 - Turbo intake pipe splits.
- BMW 3 Series (E90/F30) 320d - Oil fouling from the breather system.
- Land Rover Discovery 3/4 TDV6 - Split intercooler hoses causing signal turbulence.
How P0104 is fixed
- Reseat and inspect MAF connector
- Clean MAF with dedicated spray
- Replace MAF if cleaning doesn't clear it
- Repair intake boot
The P0104 misdiagnosis that wastes money
I see a lot of lads immediately chucking a new MAF sensor at this, usually a cheap £30 eBay special that doesn't work out of the box. But with P0104, the 'intermittent' bit is the clue. More often than not, it’s a cracked air intake hose or a pin fitment issue in the plug. I’ve had many a Vauxhall Insignia come in where the wiring harness is just a tad too short, and every time the engine rocks on its mounts, it tugs the wires and trips this code. Replacing the sensor won't fix a broken wire hidden in the loom.
What a UK garage should charge for P0104
A diagnostic plug-in at an indie will run you £40 to £70. If it's just a split intake boot, you're looking at £60-£100 fitted. A genuine Bosch or Denso MAF sensor usually costs between £120 and £220 depending on the motor, plus half an hour's labour. If you go to a main dealer, expect to pay north of £350 for the same job. Beware of 'white box' sensors from local factors; they often cause more grief than they solve.
P0104 repair cost in the UK
Most P0104 repairs land between £25–£320 including parts and labour. The spread is wide because the cheap fix (a sensor, a hose, a leak) and the expensive fix (a major component) throw the same code — which is why a proper diagnosis before parts are bought saves the most money.
Bob's tip on P0104
Before you let a garage sell you a £200 Bosch sensor, ask them to do a 'wiggle test' on the wiring harness while watching the live data on their scanner. If the MAF reading jumps or drops out when they shake the wires, it’s a harness repair you need, not a new part. Also, if you’ve got an aftermarket 'oiled' performance filter (like a K&N), that oil often coats the sensor wire and causes these drop-outs. Clean it first with a proper MAF cleaner spray before condemning the unit.
Can you drive with P0104?
Yes, but expect hesitation and poor MPG.
Urgency: medium.