Hey, I have a 2005 chevy venture and i have in the last 2 weeks have changed 6 plugs, egr valve, fuel filter, evap purge solenoid, camshaft position sensor, o2 sensor (bank 1) and replaced a couple vacuum lines and fittings. Now I am throwing codes p0131, P0135, P0401, and P0171. Now it drives fine unless you are stopped then it boggs down and the lights dim, sometimes/usually dies. Alternator is good. I have already thrown $600 at this van and i don't want to get rid of it but I'm stumped and broke. Any help would be appreciated!!

 

You need to do less parts replacing , and more measuring/testing. All you've done is waste money and you're no closer to understanding what the issue is.

start with basic stuff ... fuel pressure, voltage, fuel trims, smoke test, etc. replacing sensors doesn't do squat if the wires or connectors are bad, right? Use a meter to test.
Type your codes into obd-codes.com and follow the diagnosing steps there.