Diagnosing Diesel Emissions Right the First Time

Modern diesel engines rely on sophisticated systems like Selective Catalytic Reduction (SCR) to meet strict EPA emissions standards for Nitrogen Oxides (NOx). As a mechanic or service manager, when a truck rolls in with a "SCR Performance Low" or a P20EE code, you know you're on the clock—the engine will derate, and an incorrect diagnosis means expensive, unnecessary parts replacement and unbillable labor.

That's where the KANE-EGA1NO NOx Gas Analyzer becomes your essential diagnostic tool.

The SCR System: How it Fights NOx

Nitrogen Oxides are harmful gases created by the high combustion temperatures in a diesel engine. To combat this, modern vehicles inject Diesel Exhaust Fluid (DEF), often known as AdBlue, into the exhaust stream before it enters the SCR catalyst. The urea in the DEF converts to ammonia, which then reacts with the NOx in the SCR to convert the pollutants into harmless nitrogen and water. The goal of a healthy system is an approximate 90% reduction in NOx at the tailpipe.

Why Onboard Sensors Aren't Enough

Your vehicle's onboard diagnostics (OBD) and its NOx sensors are crucial, but they have a critical limitation: they cannot differentiate between NOx and ammonia.

• If the DEF system over-injects AdBlue, the excess ammonia—known as ammonia slip—is read by the downstream NOx sensor as high NOx, resulting in a false reading and an incorrect fault code.

• Conversely, if a NOx sensor is faulty, the onboard computer might over- or under-compensate the DEF injection, leading to system failure that can only be accurately confirmed by an independent tool.

The onboard computer can only see the data from its own, potentially misleading, sensors. Using a scan tool alone means you're operating with incomplete, possibly inaccurate, data.

The KANE-EGA1NO Advantage: Pinpoint Accuracy

The KANE-EGA1NO analyzer is the only reliable way to get an accurate, real-time measurement of the processed NOx emissions exiting the tailpipe. It eliminates the guesswork and allows you to confirm if a failure is due to a faulty sensor, a clogged SCR catalyst, or an issue with the DEF injection itself.

Key Diagnostic Step:

1. Verify Sensors First: By temporarily disconnecting the DEF injector and driving the vehicle to deplete the ammonia stored in the SCR, you can force the system to a steady state.

2. Compare Readings: You then compare the readings from NOx Sensor 1 (pre-SCR), NOx Sensor 2 (post-SCR), and the KANE-EGA1NO at the tailpipe. All three should read approximately the same high level. If an onboard sensor's reading is different, you've immediately isolated a faulty sensor.

3. Confirm System Performance: Reconnecting the DEF injector and performing another road test, you can use the KANE-EGA1NO to see if the system achieves the target 90% NOx reduction. If it doesn't, you can then focus your diagnosis on the DEF injector or the catalyst itself.

The included Pass/Fail guide gives you the precise PPM readings to confirm your diagnosis immediately (guide found here). For example, if Sensor 1 reads 400 ppm, Sensor 2 reads 800 ppm, and the KANE-EGA1NO reads 400 ppm, you know the SCR & Slip Catalyst is TOTALLY FAILED.

The KANE-EGA1NO's fast calibration, portability for shop and road tests, and ability to capture Pre & Post repair reports make it an indispensable tool. Stop wasting time and money on speculative repairs. Equip your shop with ANSED Diagnostics and the KANE-EGA1NO to ensure quick, accurate, and profitable diesel emissions diagnosis.

Read the full whitepaper here.