Bank 1 rich at idle only.
P2188 — also written P2188, P 2188, 2188 — is the OBD-II code for system too rich at idle (bank 1). Same code, same fix: this page covers every spelling of it.
Your engine is getting too much petrol or not enough air when you're sat idling, and it's usually down to a leaky injector or a dodgy purge valve on a petrol turbo. I see this constantly on Volkswagens and Fords where the fuel-to-air mix has gone belly up at the lights.
P2188 is a fuel & air fault code, typically costing £80–£600 to put right in a UK garage.
What P2188 actually feels like to drive
- The car hunts and surges when sitting at traffic lights, nearly stalling.
- A heavy smell of unburnt petrol from the tailpipe when you're idling in the driveway.
- Black soot buildup around the exhaust tip that wasn't there last month.
- The engine 'hiccups' or feels lumpy specifically when you're waiting at a junction.
- Start-stop system stops working because the ECU knows the fueling is all over the shop.
What causes P2188?
- Leaking injector
- Stuck-open EGR
- MAF fault
UK vehicles that throw P2188 most often
- VW Golf / Scirocco 2.0 TFSI (EA113/EA888) 2006-2015
- Ford Focus 1.0 EcoBoost (M1DA/M2DA) 2012-2018
- Vauxhall Astra J 1.4 Turbo (A14NET) 2009-2015
- Mini Cooper S 1.6T (R56 N14/N18 engine) 2007-2013
- Audi A3 1.8 / 2.0 TFSI 2008-2016
How P2188 is fixed
- Injector test
- EGR inspection
The P2188 misdiagnosis that wastes money
I see folks racing to Euro Car Parts for a new MAF sensor the second they see this code, but more often than not, they’re throwing seventy quid down the drain. In my experience, especially on the VAG 2.0 TFSI engines, it’s usually the PCV valve (oil separator) diaphragm that’s split or a leaking high-pressure fuel pump dumping petrol directly into the oil. Don't just swap the sensor because a cheap scanner told you to; you’ll end up with the same EML on three days later.
What a UK garage should charge for P2188
A basic diagnostic plug-in will run you £50 to £80 depending on the local rate. If it's just a Bosch purge valve, you're looking at £120 fitted. However, if I have to pull the injectors and send them off for testing, or replace a high-pressure fuel pump (HPFP), you’re looking at £450 to £600. A genuine Denso or Bosch MAF sensor usually sits around £140 plus half an hour's labour. Avoid the £30 eBay specials—they're rubbish.
P2188 repair cost in the UK
Most P2188 repairs land between £80–£600 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 P2188
Before you let a garage sell you four new injectors, ask them to check the "Long Term Fuel Trims" at idle versus 3,000 RPM. If the numbers are sky-high at idle but normal when you're revving it, it's an air/vacuum leak or a purge valve issue, not a dead sensor. If the car smells like a petrol station when you pull the oil dipstick, your high-pressure pump is leaking fuel into the sump. Insist on a 'leak-off test' for the injectors—don't let them guess with your wallet.
Can you drive with P2188?
Drivable.
Urgency: medium.