Inflate the tire and give it another test drive if it still does it then
there is a suspension problem.

Can't go up a hill - sounds like the catalytic converter is plugged.

Went to have a look at a gorgeous Nissan Primera P11 today. Was
virtually prepared to buy it. It was clean, perhaps too clean for an
eight year old - frankly my first reaction is that it had been resprayed...

But body work was spectacular.

The only things that put me off...

Electric Window switch was sticking...
Gear change on 1st to 2nd caused an unusual clonking sound...
The engine was warm when I went to view...
The engine seemed to lack power...

Don't get me wrong here... it was an SR20De, and it certainly had some
oomph in 1st gear, but going up a hill was a nightmare. Had to drag it
into 3rd to make any progress. You could press the accelerator all the
way down and it wouldn't do anything.

I plugged my Blazt cable in, and all the sensors looked fine, and yet it
seemed to lack power.

The engine looked fine under the filler cap, no gunk.

Oh and the car veered off to one side, but he said it was because the
tire was underinflated.

Have I passed up a bargain, or have I safely ignored a Piece of S***?