P1516 and reduced engine power
 

Yeah, I've that code going on with my 2003 Tahoe, 175,000 miles. It has never had that one until a few months ago. Code said throttle pedal sensor so I put on a new one and all was good for 4 months then it returned. This time I replaced the throttle position sensor and it was good for 4 days. No engine work had been done to possibly cause wiring damage. This truck is rust free and grounds are clean. Recently it seemed to be cold temp related but not every time. 5 times late yesterday and 4 this morning. Kind of a hindrance when having to travel the highway to work. Due to the miles and age, I didn't mind replacing those two sensors. So, what now?
Searching the 'net there are all kinds of fixes. What worked for you?

Re: P1516 and reduced engine power
 

Is your replacement TPS a GM part or aftermarket?

Re: P1516 and reduced engine power
 

It is aftermarket. I am now looking for an AC Delco complete throttle body and TPS. At 275,000 miles, it's time.

Re: P1516 and reduced engine power
 

New Delco throttle body assembly arrived and installed. Seems to have cured the problem.

Re: P1516 and reduced engine power
 

Yeah. That seems to be the way a lot of aftermarket electronics end up.
Jeep crank position sensors are a nasty one. Probing the output from aftermarket CPS and good OEM Jeep CPS with a scope is a conundrum. The signals look exactly the same but the aftermarket Jeep CPS causes all kinds of strange ghost in the machine kind of problems that disappear when you plug in the OEM part.

Glad you fixed the issue.