Short answer / Key takeaway: This guide is for UK Mazda owners, workshop mechanics and engine buyers investigating a PEX3 reference, e-Skyactiv-G problems or replacement options. Mazda documents relevant 2.0-litre SKYACTIV-G petrol specifications, but the reviewed sources do not prove the exact PEX3, 122-output or model mapping, so confirm the registration, physical engine identity and mild-hybrid/control configuration before ordering. Then compare tested used, reconditioned or supply-and-fit quotes by evidence, included hardware, warranty and fitting scope.
MAZDA ENGINE CODE • PEX3
Mazda PEX3 Engine (2.0L e-Skyactiv-G 122): Specs, Common Faults & Replacement
Mazda PEX3 2.0L e-Skyactiv-G 122 engine guide for the Mazda 3, CX-30 - specs, common faults and reconditioned or tested used replacement options with warranty.
✓ Used & reconditioned routes
✓ Supply only or fitted
✓ Vehicle-specific checks before commitment
ENGINE SIZE
2.0L
FUEL TYPE
Petrol (Mild Hybrid)
ENGINE CODE
PEX3 replacement engine options
Related engine size:Mazda 2.0L Engines →
UK's Most Requested Engines — Based on 5,760+ Real Quotes (Last 90 Days)
These are the engines UK drivers ask us about most, ranked by real enquiry traffic through our network — useful context when you're weighing how much homework your engine deserves.
1
Most requested
Mazda 6 2.2 SkyActiv-D Engine SH-VPTR / SHY family
Used & reconditioned · Business seller
Get multiple engine quotes across the UK
Typical fitment: Mazda 6
Engine option: SH-VPTR / SHY family
Top UK demand — the diesel most often researched for replacement
Seller from trusted UK supplier network
2
Mazda CX-5 2.2 SkyActiv-D Engine SHY1 / SHY4 / SHY6
Used & reconditioned · Business seller
Get multiple engine quotes across the UK
Typical fitment: CX-5
Engine option: SHY1 / SHY4 / SHY6
High demand; output and code vary by year
Seller from trusted UK supplier network
3
Mazda 3 2.0 SkyActiv-G Engine PE-VPS
Used & reconditioned · Business seller
Get multiple engine quotes across the UK
Typical fitment: Mazda 3
Engine option: PE-VPS
Volume petrol with several applications
Seller from trusted UK supplier network
4
Mazda CX-3 1.5 SkyActiv-D Engine S5-DPTR
Used & reconditioned · Business seller
Get multiple engine quotes across the UK
Typical fitment: CX-3
Engine option: S5-DPTR
Steady CX-3 DK diesel demand
Seller from trusted UK supplier network
5
Mazda 2 1.5 SkyActiv-G Engine P5-VPS
Used & reconditioned · Business seller
Get multiple engine quotes across the UK
Typical fitment: Mazda 2
Engine option: P5-VPS
Small-car petrol volume
Seller from trusted UK supplier network
6
Mazda MX-5 1.5 / 2.0 SkyActiv-G Engine
Used & reconditioned · Business seller
Get multiple engine quotes across the UK
Typical fitment: MX-5
Enthusiast-driven demand
Seller from trusted UK supplier network
7
Mazda CX-60 3.3 e-Skyactiv D Engine T3Y4
Used & reconditioned · Business seller
Get multiple engine quotes across the UK
Typical fitment: CX-60
Engine option: T3Y4
Newest diesel; near-new donor market
Seller from trusted UK supplier network
8
Mazda CX-30 2.0 SkyActiv-G Engine PE-VPS / PEX family
Used & reconditioned · Business seller
Get multiple engine quotes across the UK
Typical fitment: CX-30
Engine option: PE-VPS / PEX family
Growing volume
Seller from trusted UK supplier network
9
Mazda BT-50 3.2 Duratorq diesel Engine P5-AT
Used & reconditioned · Business seller
Get multiple engine quotes across the UK
Typical fitment: BT-50
Engine option: P5-AT
Commercial workhorse demand
Seller from trusted UK supplier network
10
Mazda 2.5 SkyActiv-G Petrol Engine
Used & reconditioned · Business seller
Get multiple engine quotes across the UK
Typical fitment: CX-5, Mazda 6, CX-30, Mazda 3
Higher-capacity petrol
Seller from trusted UK supplier network
Reviewed Mazda engine guidance
Reviewed by the MazdaReplacementEngines.co.uk technical content team. Last updated: 21 September 2026.
MazdaReplacementEngines.co.uk is an independent UK replacement-engine comparison service for Mazda owners and workshops and is not affiliated with Mazda Motor Corporation.
If PEX3 appears in a Mazda 3 replacement-engine enquiry, do not order from that reference alone. The live page identifies PEX3 as a 2.0-litre e-SKYACTIV-G 122 mild-hybrid petrol engine and links it with Mazda 3 and CX-30, but the reviewed Mazda manufacturer evidence does not establish that exact code/application mapping. This guide is for UK Mazda owners, garages and engine buyers who need to verify the identifier first and then compare tested used, reconditioned or supply-and-fit routes.
Who this guide is for
Who this page is for
UK Mazda owners, independent garages and replacement-engine buyers who have been given a PEX3 reference and need to confirm what it identifies, whether it matches their vehicle and which replacement route is appropriate.
Engine definition
What is PEX3 on a Mazda engine enquiry?
Conversational definition.
Answer
PEX3 should be treated as an engine identifier requiring vehicle-specific verification. The live page describes it as a 2.0-litre e-SKYACTIV-G 122 mild-hybrid petrol engine, but that exact description should remain conditional until an authoritative Mazda/service/parts application record supports it.
Specifications and evidence
| Manufacturer-backed context | What it establishes |
|---|---|
| Mazda3 powertrain documentation | SKYACTIV-G / e-SKYACTIV G are Mazda3 petrol powertrain categories in documented markets/specifications |
| Mazda3 SKYACTIV-G 2.0 specification | Relevant Mazda3 manuals document 1,998 cc, DOHC 16-valve inline-four SKYACTIV-G 2.0 configurations |
| Evidence limitation | These facts do not by themselves prove PEX3 ↔ e-SKYACTIV-G 122 or PEX3 ↔ Mazda 3/CX-30 application |
What does Mazda officially confirm about Mazda3 petrol engines?
Source-backed question.
Answer
Mazda's official Mazda3 documentation identifies SKYACTIV-G and e-SKYACTIV G petrol powertrain categories. Official Mazda3 specifications also document 2.0-litre SKYACTIV-G configurations in relevant variants, but these manufacturer records should not be used as standalone proof that PEX3 is a particular 2.0-litre e-SKYACTIV-G code or always has a 122 output.
Compatibility and fitment checks
Does PEX3 definitely fit a Mazda 3 or CX-30?
Conversational query.
Answer
Not from the evidence reviewed so far. Confirm the UK registration, physical engine identification, production specification, transmission/drivetrain, mild-hybrid/control hardware, emissions/electronics and relevant part/application references before accepting compatibility.
Hybrid and electrical checks
Why does mild-hybrid hardware matter when replacing an engine?
Topical depth.
Answer
Where an e-SKYACTIV G mild-hybrid configuration is confirmed, the replacement decision is not based on engine capacity alone. The fitted electrical/control hardware, sensors, ancillaries, calibration and component scope can affect the installation and commissioning requirements.
Diagnosis before replacement
Should I replace a PEX3 engine because of a warning light or poor running?
Natural-language question.
Answer
No, not automatically. Diagnostic scanning and mechanical checks should distinguish internal engine damage from ignition, fuelling, intake, lubrication, cooling, emissions, sensor, electrical and mild-hybrid/control-system faults before complete replacement is authorised.
Compare replacement routes
| Route | What to compare |
|---|---|
| Tested used | Exact identity, disclosed mileage, provenance, testing/condition evidence, included components/electronics, supplier warranty |
| Reconditioned | Documented work, replaced parts, inspections/measurements, test results, included hardware, supplier warranty |
| Supply & fit | Verified engine, removal/installation, fluids/filters, ancillary/electrical transfer, relevant coding/adaptation/calibration, commissioning, road test, timing and warranty |
Which PEX3 replacement route should I compare?
Decision query.
Answer
Once the engine identity and diagnosis are confirmed, compare tested used, reconditioned and supply-and-fit routes on technical evidence, included components, warranty, total cost and installation requirements rather than headline price alone.
Verify the engine before ordering
Confirm UK registration and full vehicle specification.
Photograph or record physical engine identification.
Confirm production period and derivative.
Confirm transmission and drivetrain.
Confirm mild-hybrid/electrical and emissions/control configuration.
Review used mileage/provenance/testing evidence or reconditioning records.
Confirm included components/electronics.
Get warranty, delivery and fitting/commissioning scope in writing.
How do I verify PEX3 before buying?
Conversational query.
Answer
Start with the UK registration, then record the physical engine identification and require the proposed unit to be matched to the individual vehicle in writing. If e-SKYACTIV G is confirmed, also verify the relevant mild-hybrid/electrical configuration and commissioning requirements.
Evidence to request
What proof should I ask for with a replacement engine?
Original-experience support.
Answer
For a used engine, ask for available donor/provenance records, disclosed mileage and genuine testing or condition evidence. For a reconditioned engine, ask for documented work, replaced parts and test results. Evidence should come from the actual engine/supplier process, not be created just to satisfy an SEO audit.
When available, add genuine owned assets: a PEX3/engine-identification photograph, anonymised supplier test checklist, condition report, provenance example or reconditioning record. Do not fabricate screenshots, tests or customer cases.
Original experience.
What to compare in a quote
What should a PEX3 replacement-engine quote include?
BOFU query.
Answer
A written quote should identify the proposed engine and state condition, used-engine mileage where applicable, price, warranty, delivery, fitting if requested, expected timing and supplier identity/details. Where mild-hybrid hardware is relevant, clarify included components and installation/commissioning scope too.
Additional detail
Relevant suppliers can send competing quotes by email and SMS/WhatsApp after an enquiry. Availability is confirmed after the enquiry rather than shown as real-time website stock, and MazdaReplacementEngines.co.uk does not charge customers for the quote-comparison service.
Verification data to record
What data can be safely published on this PEX3 page?
Use numerical specifications only when an exact reliable source supports the value and its application. Do not invent failure rates, demand rankings, average prices or quote volumes simply to create a data signal.
Source-backed context
A relevant official Mazda3 manual documents SKYACTIV-G 2.0 at 1,998 cc with a DOHC 16-valve inline-four layout in the specification it covers. Use that only as Mazda3 SKYACTIV-G 2.0 context; it is not proof of the PEX3 code or the live page's 122-output claim.
PEX3 engine FAQs
What is PEX3?
PEX3 is treated here as an engine identifier that requires vehicle-specific verification. Do not use the reference alone as final proof of engine type, output or compatibility.
Is PEX3 definitely a 2.0 e-SKYACTIV-G 122 engine?
The live page says so, but the reviewed Mazda manufacturer evidence does not establish that exact PEX3 mapping. Keep the claim conditional until an authoritative application source is approved.
Can I buy a tested used PEX3 engine?
Where a correctly matched unit is available, compare exact identity, disclosed mileage, provenance, testing/condition evidence, included components/electronics and supplier warranty.
Can I get a reconditioned PEX3 engine?
Where a matching option is available, ask for documented work, replaced parts, inspections or measurements, test results, included hardware and supplier warranty.
Can I request PEX3 supply and fit?
Yes, where a suitable matched unit and workshop route are available. The quote should define installation, relevant coding/adaptation/calibration, commissioning, road testing and warranty.
How much does a PEX3 replacement engine cost?
There is no reliable single price because the quote depends on exact identity, condition, used mileage where applicable, availability, included hardware, delivery and fitting requirements.
Does a mild-hybrid warning light mean the engine needs replacing?
Not automatically. Electrical, sensor, control, ignition, fuelling or other faults can produce serious symptoms without proving complete internal engine failure.
Can I order PEX3 using my registration alone?
The UK registration is the vehicle-level starting point, but physical engine identification and relevant mild-hybrid/control specification should also be checked before compatibility is accepted.
Source-backed information
Authoritative Mazda sources
External source support.
External source 1
Mazda Motor Corporation — Mazda3 Owner's Manual, Identification Numbers / engine categories: https://owners-manual.mazda.com/gen/en/mazda3/mazda3_8jr6ee20e.pdf
External source 2
Mazda Motor Corporation — Mazda3 Owner's Manual, engine specifications: https://owners-manual.mazda.com/gen/en/mazda3/mazda3_8hc2eo19a.pdf
Limitation
Neither reviewed official Mazda document explicitly establishes PEX3 as the engine code or proves PEX3 ↔ e-SKYACTIV-G 122 ↔ Mazda 3/CX-30. Do not overextend these citations.
READY FOR THE NEXT STEP?
Get Engine Quotes →Get Mazda replacement-engine quotes
Get PEX3 replacement-engine quotes Share the UK registration, physical engine identification, diagnostic information and whether you need engine only or supply & fit. Relevant suppliers can verify the requirement and provide written quotes for comparison.
Reviewed Mazda engine guidance
Reviewed by the MazdaReplacementEngines.co.uk technical content team. Last updated: 15 September 2026.
MazdaReplacementEngines.co.uk is an independent UK replacement-engine comparison service for Mazda owners and workshops and is not affiliated with Mazda Motor Corporation.