Last Problem - Reduced Engine Output
Thread Starter
Instructor
Joined: Jan 2020
Posts: 143
Likes: 12
From: Beaumont, Southeast Texas
Last Problem - Reduced Engine Output
With a tremendous amount of support from you guys I have successfully rebuilt my first LT1 and mounted a Z06 blower on it. The car is running and I have been driving it but it has not been tuned yet, and here’s why. About 15 seconds after starting the car it throws the Reduced Engine Output light. BUT the car does not go into limp mode nor does it appear to be speed limited. I have one permanent DTC, 1101. I believe this is because the conversion took the temperature measurement wire out of the MAS and put it in the blowers pressurized MAS. The LT1 harness doesn’t have the wires in place for both. My tuner doesn’t want to put the car on the dyno until that REO light is resolved. Am I wrong in thinking the problem lies in the MAS because that function is not working?
PS there is no Check Engine light
PS there is no Check Engine light
Last edited by Pjmc15Z51; Aug 1, 2021 at 07:14 PM.
Burning Brakes
Joined: Nov 2016
Posts: 1,188
Likes: 436
From: San Dimas CA
I'm not sure what you are calling an MAS, but DTC P1101 indicates that the calculated air flow is less than the actual air flow. The MAF and MAP sensors are used for this calculation. Check these sensor readings with a scan tool. With the engine off, the MAP should read barometric pressure. With the engine idling, the MAF should read approximately 6.5 gm/sec. Check both for a smooth response with changes in throttle position.
Thread Starter
Instructor
Joined: Jan 2020
Posts: 143
Likes: 12
From: Beaumont, Southeast Texas
Good input. The sensor I’m calling MAS is the one in the CAI by the air filter. Since the supercharger kit hijacked the temperature measurement wire from that sensor I wonder if the ECM is not getting an accurate reading? But this is probably a common practice with LT1 supercharger kits so perhaps it’s something my tuner needs to deal with. Your suggestion to use a scan tool will give me further insight.
Thread Starter
Instructor
Joined: Jan 2020
Posts: 143
Likes: 12
From: Beaumont, Southeast Texas
While researching the problem here I ran across Ben at HPTuners who has experience with this setup. I made contact with him and he will be sending me a tune. The car has several bad manners related to the cam that are tuning issues that will also be addressed. I’ve read lots of good things about Ben so I’m looking forward to working with him. I’m confident the problem will be resolved.
