EVAP fuel vapour smoke test in
Slough.
EVAP system leak triggering P0455, P0456, P0457 or an MOT fail? We smoke test the fuel vapour system at our Slough workshop and find the leak first time. No nonsense. No hidden prices. Book in today.
⭐⭐⭐⭐⭐ 4.9 out of 5 from 500+ Google reviews. Trusted by drivers across Slough since 2019
- ✓6 months interest-free, up to £3,000
- ✓Same-day slots available in Slough
- ✓EVAP and MOT retest done same day
EVAP Emissions Smoke Test for MOT Failures in Slough
EVAP faults are not boost leaks, but they use the same smoke testing principle. The Evaporative Emissions Control system traps fuel vapour from the tank and feeds it back into the engine to burn. When it springs a leak, you get a P0455 (large leak), P0456 (small leak) or P0457 (loose filler cap) fault code, a check engine light, and on newer cars an MOT failure for emissions readiness.
We EVAP-smoke test cars at our Slough workshop every week, particularly the days before and after MOT season. The leak is rarely where the code suggests. Our smoke test finds it properly the first time, with no parts guessing.
Where EVAP leaks usually hide
- Fuel filler cap not sealing. the a fair amount fix. Always check first. Often the answer on older Ford, Vauxhall and Hyundai
- Charcoal canister vent valve stuck open. common on VW, Audi, Ford, Hyundai and Kia. P0455 large leak on the scan tool
- Cracked EVAP hose under the car. exposed to road salt and stone chips. Often cracked between the tank and the canister
- Purge valve / N80 valve stuck open. VAG, Mini and BMW failure. Easy fix once identified
- Fuel tank pressure sensor seal. small leak in the tank-top seal, only detected by a careful smoke test
- Filler neck rust holes. older Slough cars from the salt-belt months. We will be honest if the neck needs welding or replacing
How an EVAP smoke test is different from boost-leak
An EVAP system runs at very low pressure, not boost pressure, so we use a low-pressure smoke generator connected to the EVAP service port (or via the purge valve, depending on car). We seal the system and watch where the smoke escapes. On most cars the leak shows in under 15 minutes.
We then identify whether it is a quick fix (cap, hose clamp, valve replacement) or a bigger job (charcoal canister, fuel tank seal). You get a fixed quote before any chargeable repair starts at our Berkshire workshop. No surprises.
MOT retest, the same-day fix
Failed your MOT in Slough on EVAP readiness or fuel system warning lights? We can usually smoke-test, fix and clear the codes the same day. If the original MOT was here in Slough we will arrange the retest. If it was elsewhere, we will get the car ready for you to take back to your test centre.
Drivers across Berkshire come to us specifically for honest EVAP work because the chain garages tend to throw new parts at the car hoping for a fix. We do not. We diagnose, quote, fix and retest, in that order.
Where we are and who we cover
EVAP smoke testing and MOT-fail diagnosis for drivers across Slough, Langley, Colnbrook, Datchet, Windsor, Maidenhead, Uxbridge and Gerrards Cross. Honest Berkshire workshop, five minutes from M4 J5 at SL3 7EW.
EVAP code or MOT fail? Call 01753 439115 or WhatsApp the Onyx Autocentre team on 07393 580281 with your reg and we will book an EVAP smoke test at our Slough workshop. 01753 439115 or WhatsApp 07393 580281.
More on boost leak & smoke test: Turbo Boost Leak Smoke Test in Slough · BMW N54 / N55 Charge Pipe Boost Leak. Found in Slough · VW / Audi 2.0 TFSI PCV and Boost Leak Test in Slough · Intercooler or Intake Leak? Diagnosed Across Berkshire · Back to Boost Leak & Smoke Test
EVAP Emissions Smoke Test for MOT Failures in Slough in Slough and across Berkshire
Onyx Autocentre is based in Slough, Berkshire and we look after cars from across the SL postcodes every day. Whether you're driving in from central Slough, Poyleor Langley, we'll book your evap emissions smoke test for mot failures in slough around your schedule. Same Slough workshop, same trusted team, same standard on every evap emissions smoke test for mot failures in slough job.
All our services
Every service we offer at our Slough workshop. Tap a tile to find out more.
- Air Bag RepairsFind out more
- Alloy Wheel Crack WeldingFind out more
- Alloy Wheel RefurbishmentFind out more
- Alloy Wheel WeldingFind out more
- Auto ElectricsFind out more
- Body Kit FittingFind out more
- Boost Leak & Smoke TestFind out more
- CambeltsFind out more
- Car Air ConditioningFind out more
- Car BatteriesFind out more
- Car BrakesFind out more
- Car ExhaustsFind out more
- Car ModificationsFind out more
- Car RepairsFind out more
- Car Safety ChecksFind out more
- Car ServicingFind out more
- Car TyresFind out more
- Carbon CleaningFind out more
- Cheap Car TyresFind out more
- Clutch ReplacementFind out more
- Diesel Performance ECU TuningFind out more
- Diesel TuningFind out more
- Dyno TestingFind out more
- ECU RemappingFind out more
- Engine DiagnosticsFind out more
- Engine ManagementFind out more
- Engine RebuildsFind out more
- Engine TuningFind out more
- Fleet MaintenanceFind out more
- Gearbox ServicingFind out more
- Gearbox TCU RemappingFind out more
- Haldex ServicingFind out more
- Head Gasket RepairsFind out more
- In-Car EntertainmentFind out more
- Mechanical RepairsFind out more
- MOT Failure RepairFind out more
- Nitrogen Oxide (NOx) Sensor RepairsFind out more
- Number PlatesFind out more
- Oil & Filter ChangeFind out more
- Parking SensorsFind out more
- Powder Coating for Alloy WheelsFind out more
- SteeringFind out more
- SuspensionFind out more
- Timing Belt ReplacementFind out more
- Trade Alloy Wheel RepairFind out more
- Turbo Intake CleaningFind out more
- Van Repairs & ServicingFind out more
- Vehicle SecurityFind out more
- Wet Belt ReplacementFind out more
- Wheel BalancingFind out more
- Window TintingFind out more
What Our Customers Say
Rated 5 Stars on Google by drivers across Slough and Berkshire
"Took my BMW here for an oil change and oil filter and the service was spot on. Really friendly team, got the car booked in quickly and the job was done properly with no hassle."
"Highly recommend this garage. After contacting a few other garages who didn't want to take my car in for diagnostics, these guys were happy to help. They diagnosed and fixed an engine fuel leak issue professionally and efficiently. Great service and very reliable. I'll definitely use them again."
"Very nice experience at Onyx — they took me in immediately and completed the DRL module swap efficiently. I have no regrets and would highly recommend."
"I brought my car to Onyx after visiting many other mechanics who failed to sort out issues with my vehicle. The mechanics here clearly explained the issues with the vehicle and fixed them quickly. Amazing service and wonderful people, highly recommend."
"These guys are always polite and welcoming. I've taken multiple vehicles here and the service received has been excellent."
"Had the front pads done here over the weekend. Second time in with Onyx and service has been top notch both times. On time, no hassle and cost effective. Highly recommend."
"Max and Ben are extremely professional and did an excellent repair on my wife's car at a great price. Max spotted the problem within 6 hours, which 2 other garages could not detect."
"I took my car to Onyx and met Ben who was friendly and I got the problem diagnosed by Ben which I had a faulty water pump. I was quoted a reasonable price and got it replaced. I was satisfied and would recommend Onyx."
"Great service, sorted out my alloy refurb at a good price and quick turnaround. Top service, highly recommend."
"A great experience with Onyx who fitted a new clutch for my Fiat 500. Super quick, friendly and well priced. Would highly recommend."
"Very friendly, no hassle effective service. Definitely recommend and will use when I need to get my alloy wheels refurbished."
"Brought my Audi S3 in for a coolant leak — the part was on back order but they managed to source one in a couple of days. Massive thanks to Ben."
"My vehicle went in for a brakes job and Ben and the team at Onyx Autocentre did an amazing job. Highly recommended."
Spread the cost over 6 months, interest-free.
Big bill? Pay the first instalment when you book, then spread the rest across up to 5 more monthly instalments, interest-free. Available on jobs up to £3,000. No setup fees, no hidden interest. FCA-authorised through Payment Assist, soft credit check, decision in minutes.
- ✓ Up to 6 months interest-free
- ✓ Available on jobs up to £3,000
- ✓ First payment at booking, rest split monthly
- ✓ Soft credit check, decision in under 2 minutes
- ✓ No setup fees, no hidden interest
Same-day slots are limited this week.
Call or WhatsApp now and get evap emissions smoke test for mot failures in slough today. Slough, Langley, Colnbrook, Windsor, Maidenhead, Uxbridge and Gerrards Cross.