gmc envoy 2002 sle

Question

P1221 and p1516 i have 2 code my engine runs and sometimes its stals and my engine ligt stay on after i shut off the engine and start again and engine is ok its intermitent what could it be???

Answer 1

P1221 Throttle position sensor 1-2 correlation

P1516 Throttle actuator control module throttle actuator position perfromance

When the code appear does the vehicle display "Reduce Engine Power " ? the reason for the question is when the engine stall while you are acclerating it would code up a P1516 and P1221 which would not cause the engine to stall but these code would be a result of the engine stalling. P1516 are usually seen when the throttle actuator is disconnected and the engine would go into a redulce engine power mode but the engine will not stall. P1221 this can be the result of the stall , as you where driving and all of a sudden the vehicle went into a stall, if anything you tried to acclerate, and because the engine could not accelerate due to the engine stall P1221 coded as a result. Depending on when the engine stall out this can be from a dirty throttle body creating a reduce idle, to a MAF sensor , Try this first, Do a throttle body cleaning and a MAF cleaning. You need to find the reason why the engine stall out.