I've been working on a hesitation/stumbling problem. I've replaced the TPS (threw a code), tune up, ignition coil, tested the TFI, and today I replaced the EGR Vacuum Regulator. It was throwing code 84, which someone directed me to replace the EVR.

I now do feel some vacuum on the line at at the EGR, whereas before, I did not. I was also getting some spark knock (I think), after the truck was all warmed up, but after a test drive, it seems to be gone.

It's still not running as smooth as I would like. When testing KOEO, it gave me a code 11, then gave me a code 33? Then, I did a KOER test, and it gave code 41 (system lean, fuel control), code 33 (EGR did not open/ respond), and code 52 (did not receive goose test). Code 52 was my fault, but what's up with the system lean and EGR not opening? Any ideas? Thanks.