Chrysler does not use a mass air flow sensor
they are a speed density setup.

They do definitely use them on our European Diesel engines, I took my bosch unit off the other day to clean it. Technical descriptions aside I would check intake airflow circuits and O2 sensor while you are at it. It has to be fuel mixture related so you need to eliminate as much as you can to do with this.

We are not talking about a turbo diesel now are we? We are talking about US cars witch Chrysler does not use maf sensors.

You said chrysler don't use a MAF when they clearly do on ours over the pond. Anyhow it will have a system that monitors air intake quantity/density and this needs to be checked in my opinion.

https://www.xcceleration.com/sd-vs-maf.htm
read

royal100805, the O/P's car is a 99 petrol magnum V6. The VM Motori put into the London cabs was much much later M8.