I'm convinced I have a clogged or otherwise malfunctioning fuel injector. I've been fighting with fuel trims being way high. I'm assuming the car is running lean somehow and contributing to my KR problem.

I've replaced every vacuum hose and I don't see anything else suspicious. I've gotten the P0171 (lean) code once or twice, but generally there'* no codes and the SES light doesn't come on.

How do I test for clogged injectors? Is there anything else I should be looking for?

I took a screenshot of the scan. Long term trim hovers around 12% under most conditions until I want to accelerate. This one was taken while cruising at 70mph, then I pressed the gas giving it maybe 1/3 throttle. You can see the MAF reacting to the extra air, but still it'* running lean. Trying to accelerate almost always causes the LTFT to max out, and the short term trim to go 10% or more.

I'm stumped!

Pull your spark plugs and look at them. A lean cylinder will look different from the rest.