My 2004 trailblazer starts up then stalls.reduced engine power is on code is p00234.

SOURCE: Reduced power code comes up and my truck stalls.

I had the same problem, and the solution was cleaning the throttle body, it does need to be completely removed to be cleaned thoroughly. I just used some brake cleaner on a rag to clean off all the carbon deposits. A friend of mine who is a dealer tech had only seen this trouble code once, and this was the solution. So far, my light has not come back on and the truck is running alot better at idle.

SOURCE: 2006 trailblazer 4x4 4.2, stalls while driving.

ok well try this when it stalls see if spark is present and if it is not and it cools down and starts then you might need to replace ignition control module good luck

SOURCE: reduced power p1516 code

P1516 Throttle Actuator Control(TAC) Module Throttle Actuator Position Performance

This is your problem and should be taken in to chevy for repair

SOURCE: CHECK ENGINE LIGHT ON AND REDUCED POWER LIGHT ON,

Replace your throttle position sensor, runs about $60.00 sit on throttle body has a round connector with three wires going o it.

SOURCE: 2002 Chevy Trailblazer

hi, those sound like throttle actuator codes. the throttle body on your vehicle should be an electronically controlled unit without wires to control actual acceration an deceleration. now, there is also an electronic switch called a potentiometer on the gas pedal that transmits signal to the throttle body to tell it what to do. most of the time, the throttle body is what goes bad here. you should also check the wiring to the unit for bad connection by wiggling the wire connector and seeing if the reduced engine power light comes on. if this happens, you will likely have to replace the wiring pigtail and the throttle body. but, in some cases, the gas pedal switch goes bad, and likely what is not allowing the transmission to shift out of park, the pcm may lock out the solenoid controlling the shifter. but, don't just run with that answer, it maybe completely wrong. i have seen more throttle bodies and wiring harnesses go bad than gas pedal switches in those vehicles. but you might want to have a shop diagnose further, it may even be two unrelated problems, or in the powertrain computer itself.