Reduced engine power

[Dcreamer]

I have a 2017 Chevy Tahoe Premier with 82k miles. I have had the reduced engine power light up and it run like crap 2 times. I have searched on here and haven't seen any info, so I thought I'd post to see if anyone else had these codes pop up. My mechanic is saying there's a P050D, P0300, and the most concerning is 20-NA-166. He says its telling him there is coolant leaking onto the head, but we don't know which one as it hasn't acted up for him. Anyone else had these codes pop? He doesn't know 100% that there is a leak so we are hesitant to tear down. He figured the repair to cost around $3k with all new parts and labor. Any advice?

 

[tirekicker]

i had these codes and it was a bad pin in the main wire harness .i would highly recommend you test injectors and electrical connections before you "tear down" anything

 

[Doubeleive]

I have a 2017 Chevy Tahoe Premier with 82k miles. I have had the reduced engine power light up and it run like crap 2 times. I have searched on here and haven't seen any info, so I thought I'd post to see if anyone else had these codes pop up. My mechanic is saying there's a P050D, P0300, and the most concerning is 20-NA-166. He says its telling him there is coolant leaking onto the head, but we don't know which one as it hasn't acted up for him. Anyone else had these codes pop? He doesn't know 100% that there is a leak so we are hesitant to tear down. He figured the repair to cost around $3k with all new parts and labor. Any advice?

Unless you are loosing coolant then it's not leaking into the head
a p050d could be set by a faulty engine coolant temperature sensor and cause a rough idle (on cold start)
if the coolant level is full, how does the temp gauge act? does it get up to normal temp in a mile or 2? (from a cold start) or does it go up to normal right away? or not read right period

 

[Doubeleive]

and if it is loosing coolant, approx how much per week or 2 weeks or month.

 

[Dcreamer]

and if it is loosing coolant, approx how much per week or 2 weeks or month.

I haven't noticed any coolant leaking. I also haven't driven it when it starts and goes into reduced power mode. Its at my mechanic right now and he's trying to get it to act up again, but it hasn't so far.

 

[Doubeleive]

I haven't noticed any coolant leaking. I also haven't driven it when it starts and goes into reduced power mode. Its at my mechanic right now and he's trying to get it to act up again, but it hasn't so far.

if it's not loosing any coolant then the TSB is not the problem, generally reduced engine power occurs when the throttle body screws up, it may only happen once in a while and it usually has a code specific to the throttle body or gas pedal (position sensor). could be a short in the harness, bad ground, temperature sensor, maf, a leak in the intake (unmetered air).