A worn Bosch unit injector reference 414720039 can disturb spray pattern and fuel metering, causing unstable running and smoke under load. Correct selection by reference number and engine code is essential before fitting a replacement.
Part identification and verified reference numbers
Bosch unit injector 414720039 is the key identifier for this refurbished replacement, and it carries the Bosch cross-reference BOSCH 0 414 720 039 as well as 0 986 441 557. This matters because unit injectors are matched to the engine’s required fuel quantity and spray characteristics, so the reference-number comparison has to be done before any fitment attempt.
The unit injector’s job is precise fuel metering into the combustion chamber, with an accurate spray pattern, pressure and quantity required for clean combustion and stable power delivery. When those internal characteristics drift, the typical fault pattern on 1.9 TDI applications includes difficult starting, rough running, loss of power, increased fuel consumption, smoke, or unstable operation under load.
For selection, the practical rule is simple: compare the removed unit’s reference number and the engine code/vehicle details against the compatibility information, then confirm the old-part markings match the intended replacement. If the reference number on the removed injector does not match 414720039, treat it as a mismatch until proven otherwise.
Representative TecDoc vehicle compatibility (1.9 TDI family)
The following TecDoc fitment rows are a representative selection for VW, SEAT, SKODA and AUDI within the 1.9 TDI family using engine codes shown in the data. This is not the complete list, so always verify by the exact part number 414720039 and the specific engine code on the vehicle.
| Make | Model | Engine | Engine code(s) | Power (as listed) | Dates (as listed) |
|---|---|---|---|---|---|
| VW | BORA I (1J2) | 1.9 TDI | ARL | 150 PS | 05/2000-05/2005 |
| SEAT | CORDOBA (6L2) | 1.9 TDI | BLT, ASZ | 131 PS | 10/2002-11/2009 |
| SKODA | FABIA I (6Y2) | 1.9 TDI RS | BLT, ASZ | 130 PS | 06/2003-03/2008 |
| AUDI | A3 (8L1) | 1.9 TDI | ASZ | 130 PS | 08/2000-05/2003 |
| VW | BORA I (1J2) | 1.9 TDI | ASZ | 130 PS | 11/2000-05/2005 |
| SEAT | IBIZA III (6L1) | 1.9 TDI | BLT, ASZ | 131 PS | 02/2002-11/2009 |
| SKODA | OCTAVIA I (1U2) | 1.9 TDI | ASZ | 130 PS | 09/2002-09/2004 |
| AUDI | A3 (8L1) | 1.9 TDI quattro | ASZ | 130 PS | 08/2000-05/2003 |
| VW | BORA I (1J2) | 1.9 TDI 4motion | ARL | 150 PS | 05/2000-05/2005 |
| SEAT | IBIZA III (6L1) | 1.9 TDI Cupra R | BPX, BUK | 160 PS | 03/2004-02/2008 |
Fitment checks using old-part number, engine code and vehicle data
Start with the removed unit injector reference number and match it to 414720039. This is the fastest way to avoid a wrong fitment, especially when the vehicle is in the 1.9 TDI range with multiple engine codes such as ARL, ASZ, BLT, BPX and BUK.
Next, confirm the engine code on the vehicle matches the engine code family listed for this injector selection. The data shows compatibility across ARL and ASZ in VW BORA I (1J2) and AUDI A3 (8L1), plus BLT/ASZ in SEAT CORDOBA (6L2) and SKODA FABIA I (6Y2), and BPX/BUK in SEAT IBIZA III (6L1). If the engine code does not align, do not assume the injector will still be correct just because the model name looks similar.
Then cross-check the injector’s reference-number set: 414720039 should align with the cross-references 0 986 441 557 and BOSCH 0 414 720 039. If your old injector markings show a different reference, treat it as a different calibration requirement and re-check before ordering.
Finally, compare vehicle details from the compatibility information to the car in front of you, because the same 1.9 TDI displacement can appear with different engine codes and power outputs in the TecDoc selection. The correct approach is reference-number and engine-code verification, not guessing based on model year alone.
Concise symptoms and selection notes for 414720039
Unit injector wear shows up as poor fuel metering and disturbed spray characteristics, and the supplied symptom set for this injector selection is consistent: difficult starting, rough running, loss of power, increased fuel consumption, smoke, and unstable operation under load. If the complaint is intermittent, still treat these symptoms as injector-related until the reference match and basic checks confirm otherwise.
When selecting a replacement, the goal is to restore accurate spray pattern, pressure and quantity so combustion stays clean and power delivery remains stable. That’s why the reference-number match to 414720039 and the cross-reference set (0 986 441 557 / BOSCH 0 414 720 039) are non-negotiable steps before fitting.
Because this is a refurbished unit injector, it should be professionally tested for accurate replacement fitment, but you still need to confirm the part number and engine code match your vehicle. A correct reference match is what prevents repeat work caused by an incompatible unit injector calibration.
Internal product link: Bosch unit injector 414720039
For the exact refurbished Bosch unit injector reference 414720039 and its compatibility notes, use this link: Bosch unit injector 414720039 (unit injector). Verify the engine code against the vehicle and confirm the reference-number match before proceeding with installation.
Frequently Asked Questions
How do I check if a Bosch unit injector matches 414720039?
Compare the reference number on the removed injector to 414720039. Then confirm the engine code on the vehicle matches the engine codes listed for this injector selection, such as ARL or ASZ. Cross-checking against 0 986 441 557 and BOSCH 0 414 720 039 can help confirm you have the right unit.
What symptoms point to a faulty VW 1.9 TDI unit injector?
Common symptoms listed for this injector selection include difficult starting, rough running, loss of power, increased fuel consumption, smoke, and unstable operation under load. These symptoms align with disturbed fuel metering and spray characteristics.
Can I fit a unit injector to a 1.9 TDI if the engine code is different?
Do not rely on model name or displacement alone. The fitment checks require matching the exact reference number 414720039 and the vehicle’s engine code to the compatibility information. If the engine code does not match, treat it as a mismatch and re-check.
What cross-references should be used with 414720039?
The supplied cross-references for this unit injector are 0 986 441 557 and BOSCH 0 414 720 039. Use these to confirm the part identification set matches what’s on the removed injector and what the compatibility data expects.
Why does an incorrect unit injector reference cause repeat problems?
A unit injector must deliver the correct fuel quantity and spray characteristics for the engine. If the reference number is wrong, fuel metering and spray pattern can be off, leading to the same symptoms again such as rough running or smoke under load.