CNFB Injector Problems – Symptoms, Causes & Fixes

Engine: CNFB 1 compatible injectors From £120

Common Injector Failures on the CNFB

The CNFB engine uses high-pressure common rail diesel injection. Over time, injector nozzles wear, seals degrade, and internal components lose calibration. This leads to a range of drivability symptoms that worsen if left unaddressed. We stock 1 tested replacement injectors for this engine from Bosch.

Vehicles fitted with the CNFB include models from Audi, Seat, Skoda, Volkswagen. If you are experiencing any of the symptoms below, your injectors may need testing or replacement.

Symptoms of Injector Failure

Related Fault Codes

P0201 P0202 P0203 P0204 P0263 P0266 P0269 P0087 P0089 P0300

How to Test CNFB Injectors

Leak-off test: Connect clear hoses to the injector return lines and compare fuel volumes at idle. The injector returning the most fuel is likely worn.

Correction values: Use a scan tool to read injector correction (IMA) values. Readings beyond ±3 mg/stroke indicate wear.

Resistance check: Measure resistance across the injector connector pins with a multimeter. Compare to manufacturer specs.

Complete Testing Guide Leak-Off Test Guide

CNFB Injector Replacement Cost

Parts (per injector)

£120–£120

Labour

£150–£400

Total (per injector)

£270–£520

Full replacement cost guide

Compatible Injectors for the CNFB1 found

0445110369Bosch

£120.00

Related Cross Reference Numbers for CNFB

0445110368 0445110646 0445110647

Related Engine Codes

CDLC CFFA CFFB CFFD CFFE CFGB

Frequently Asked Questions

What are common injector problems on the CNFB engine?

The CNFB engine commonly suffers from injector seal failure, nozzle wear causing poor spray patterns, and back-leak issues. Symptoms include rough idle, black or white exhaust smoke, hard starting, and increased fuel consumption. These issues typically appear after 100,000–150,000 miles.

How much does it cost to replace injectors on a CNFB engine?

A remanufactured injector for the CNFB engine typically costs £120–£120 per injector. Labour adds £150–£400 depending on accessibility. We found 1 compatible injectors for this engine.

Which vehicles use the CNFB engine?

The CNFB engine is found in vehicles from Audi, Seat, Skoda, Volkswagen. Common models include Audi A1, Audi A3, Audi A4, Audi A5, Audi A6.

How do I test the injectors on a CNFB engine?

Perform a leak-off test by connecting clear hoses to each injector return line and comparing fuel volumes at idle. You can also check injector correction values with a diagnostic scan tool or measure electrical resistance with a multimeter.

Injector Compatibility Checker

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Need a Replacement CNFB Injector?

We stock 1 tested replacement injectors for the CNFB engine. All remanufactured, bench-tested, and supplied with a 12-month warranty.

View All Injectors Replacement Cost Guide Call 020 3355 6581