Chevy & GMC Vans

Hello guys.

Does anyone have any knowledge about what this code (po171) refers to along with message that bank one is running lean? And it blows black smoke under load like when pulling my boat.

I also have a po420 code which I think relates to the catalytic converter. I think that's running cause I removed the cat and just ran straight. I don't think this is a problem.

Thanks in advance for any help.

How many miles on your van?

It's got 202,000 kilometers (roughly 120,000 miles)

The 420 code is low converter efficiency...generally because the cat is bad. Since yours is removed, that explains the code. The problem with the systems on these vans (OBD-2) is that the computer is looking at all the sensors and adjusts fuel accordingly. You may simply have a bad sensor that is causing a too rich condition. Bank 1 is the driver side sensors. Maybe it's time for a tune-up?