1994 530i 5-speed - Failed emissions - High hydrocarbons at idle

[Miasma]

My newly acquired E34 is having trouble passing hydrocarbon emissions at idle, all other parameters passed by a large margin at idle. All parameters including hydrocarbons passed at 2500 rpm.

1994 530i V8 5-Speed 260k miles. Runs great, smooth idle, great throttle response, no CEL, no smoke.

So what would cause a rich condition only at idle on the M60? Recently performed a tune up. Including...

Fuel filters
Aftermarket cat
Oxygen sensors
Valve cover gaskets
Spark plugs
Coolant temperature sensor (replaced after last attempt)
Oil and filter change
Water pump
Thermostat
Air filter
Cleaned the ICV
Sprayed carb cleaner on all the vacuum lines and intake gaskets with no change in idle.

Any suggestions?

Will test the FPR tomorrow.

Here is the inspection report, as you can see its only failing HC at idle. So I belive the new cat is working efficiently.

Thanks for any help at all.

[Miasma]

Replaced the TPS, FPR, and PCV plate. Passed with flying colors this time.