Running Rich /spark plugs

[Rich022]

In the middle of replacing my rod bearings so i pulled the spark plugs. All 6 plugs look pretty bad. black/dry ie. Indications of a rich burn. 6K miles on both OEM coils and NGK plugs. I would say 3K of which are hard HPDE miles.
149K miles on car. Engine all stock. I did hook up a catch can around time when i installed plugs. I maintain this car better than most/ie early oil changes etc..
No issues/check engine lights etc. Car pulls strong. Suggestions here for why my car is running rich or how I can trouble shoot ? thanks in advance.

[Slideways]

Is there a tune on it (possible if there was a previous owner)? Or maybe a blockage/restriction in the exhaust? At 149k and hard HPDE miles, the stock cats could become a problem.

One other possibility is the MAF, but those usually throw a code.

[Rich022]

No tune on engine. This is a new condition as the previous spark plug change was clean (changed those with 10K miles on them)
Good suggestions however, about 3 months ago i dropped the exhaust as i was replacing the transmission mounts. Visually, my cats (stock/original) looked good/ MAF sensor is also new ~ 3 months (changed just to change) maybe too high fuel pressures- is that even possible ?

[Shonky]

Read the long term fuel trims.

[sapote]

. Suggestions here for why my car is running rich or how I can trouble shoot ? thanks in advance.

Picture is too small and low resolution, so almost useless to see in more detail. I'd like to see the color of the tip and ceramic area.

Yes, get OBD reader and read the fuel trim, MAF in g/second, engine temp, pre and post O2 sensors, at warm engine idle.

[Rich022]

it will be a few weeks for OBD data as car is up on jack stands in the middle of rod bearing r/r. Maybe this is a clearer/higher resolution picture

[sapote]

A little darker than tan, but not too rich and it might be normal if you floored the pedal often. OBD data can tell more about it.