engine on reduced power

This happens to my 8.1 about ONCE a year, but not on any particular schedule. Since my OBDII shows no problems I just chalk it up as an ECM fluke. What I have found out that works to reset mine is to go out and throw the chassis battery disconnect switch for a few seconds. Turn it back on and everything was always fine after that. I wouldn't worry too much about it. After 90,000+ miles, my engine is still running fine and I can put up with an occasional blip.

Clean the throttle body. Check the disconnect wiring also. Ensure they are tight in the plug. Usually just a dirty throttle body.

WE had two 8.1l vortecs from 2001 to 2012. The second one pulled us along for 110,000 miles with only a replacement of the exhaust donuts at 90k. It did have some quirks. the dash would reboot from time to time - disconcerting to have the Tach and speedometer drop to -0- and all the instruments flat line and then go through their "normal" start up routine - all at 60 mph! The engine derated (reduced power setting) a couple of times when the oil foamed at high temperature. Also once while climbing through Vail CO on I70 it coughed and missed a couple of times just shy of the peak. that was heart stopping, we were pulling at about 5,000 RPM at 28 mph. Your issue sounds like it derated because of the abnormal start, it maybe oil pressure had not come up fast enough because of the long storage time.

sometimes weak battery can cause this problem it doesn't have a throttle cable its drive by wire if the gas pedal sensor and the throttle position sensor don't match up it will throw meesedge and go into default mode charge your battery and see what happens

allbrandauto wrote:
sometimes weak battery can cause this problem it doesn't have a throttle cable its drive by wire if the gas pedal sensor and the throttle position sensor don't match up it will throw meesedge and go into default mode charge your battery and see what happens

x2.
Those days every driver should have OBD scanner under the seat.
Modern engines seldom have major break-downs, but maze of sensors can trigger CEL.
It is unknown that will kill your confidence, so once you scan the code to a stupid sensor, you will be confident to continue the trip.

Mine cleared it self on the third re-start.

I would put a charger on the battery, with it disconnected. FULLY charge the battery, reconnect, and try again. Low voltage can cause screwy readings. Disconnecting can reset. Sometimes.

Thanks for the info. I did recharge the battery and it seems to have corrected the probllem. I guess I willfind out for sure when i get it on
the road.

William