Can the ECM measure Nox emissions?

[1999montana]

Just wondering if the engine management system (ECM) on the 1999 Montana van is capable of reading and adjusting for Nitrous Oxide emissions.

Anyone?

[Tech II]

No, it can't measure Nox....what it can do is adjust timing and fuel mixture, adjust egr flow, and control the cooling fan to keep engine cylinder temp down, which reduces Nox formation.....the second O2 sensor detects catalyst efficiency, which determines if the cat is working efficiently....if it is, then it's reducing Nox....but the ECM does not have any sensor that directly measures Nox.......

[1999montana]

Originally Posted by Tech II

No, it can't measure Nox....what it can do is adjust timing and fuel mixture, adjust egr flow, and control the cooling fan to keep engine cylinder temp down, which reduces Nox formation.....the second O2 sensor detects catalyst efficiency, which determines if the cat is working efficiently....if it is, then it's reducing Nox....but the ECM does not have any sensor that directly measures Nox.......

Thanks for the prompt reply. I'll expalin why I asked. Our Ontario Drive Clean program was changed in 2013 to read the diagnostics off of the OBD connector. The entire premise of the Drive Clean program was to reduce green house gases and other harmful emissions through testing and enforcement. The old test involved a dyno and emissions sniffer in the tailpipe. While the old test only measured within a limited operating range, it also gave the owner some sense for how well the vehicle was performing with subsequent tests every other year.

The new test reads the OBD connector and by not finding any codes the test concludes that the vehicle is operating as designed. The old test would trap a vehicle that had worn guides or rings as it measured carbon emissions beyond CO.

To my way of thinking, this new test simply rubber stamps a group of vehicles that have no codes, but that may not be within spec for emissions due to worn internals. If I've read through a number of other sites correctly even the O2 sensor can only compensate for so much on the exhaust side.

[antishantony]

Latest ECM are able to calculate the NOx emission value from the engine inorder to check complaince with the present EURO or NAS standard