My dad's truck threw a list of codes. He gave them to me to look up. We got
P0401 Exhaust Gas Recirculation Flow Insufficient Detected
P0404 Exhaust Gas Recirculation Circuit Range/Performance
P0405 Exhaust Gas Recirculation Sensor A Circuit Low
P1000 OBD-II Monitor Testing Incomplete

I looked the codes up on the sites decoder. Would it be safe to say that his egr is going?

 

It sure could be the EGR valve.

It is warranted to either pull and clean it or just replace it IMO.

HOWEVER, be aware:
A stuck turbo can cause EGR codes but a bad EGR can not cause turbo codes.

 

yes... is it plugged in? the batteries were recently disconnected/PCM flashed(P1000) also..

 

Can you give us some info on the truck?

year model?
miles?
mods?

 

Sorry I forgot the details.

2003 6.0l 4x4
158k miles
Bully Dog Power Pup downloader that he runs at 50% I believe.

Edit: If the turbo was sticking would there be noticable power differences?

Also thanks for all the quick replies.