so I decided this morning to try and figure out how to get my VE tables set up correctly by logging the ve error histogram, I messed up and decided I was wasting my time. so I put everything back where it was and my afr was the same as when I was messing with my ve only, so I drove around thinking it would go back eventually (everything was turned back to normal) suddenly "engine power reduce" and it got real lean and seemed like I was running on 2 cylinders.. pulled over cleared the dtc's which was p068 and some p12** something or other, it started right up shortly it did it twice later same scenario. I bought a new maf sensor and popped it in and did a "write entire" on hptuners and it went back to normal.... then shortly "engine power reduce! I then went and made my high octane spark to my low octane spark and switched my p068 from 800 rpms to 8000......LATER I get a CEL and almost feels like it wants to do it again but doesn't.. I'm scared it's going to do it again. Why would gm feel the need to have this pop on while driving? why not pop on a light instead, seems like the power reduce will cause more damage than what the computer may see.

I highly doubt my recently ported throttle body is the problem, because the plates weren't touched they are in the same position.

what causes engine power reduce? what codes?.

 

tb might be the issue. if it was though it would throw codes for the TPS at the LEAST. turn ur key on accesory have a friend there or something, pop of the intake tube and have your friend slow go to WOT whle on accesory to see if the fly fully opens or to see if it flutters. i agree with the engine power reduced. when my car went into that my afr was like 16.xx and just to get up a hill it would go to 12.4 with like 50% throttle. when it was OFF the limp mode (erased codes)... afr was perfect lol 14.6-15.1 than obviously 1 minute later bang back into limp mode <3 and leaning out

 

idk man, now I just get dtc's p1182 and p0420

 

420 is cat efficency

 

ya, I know. apparently it is low efficiency w.e, I disabled that dtc as well as the other, made it to no longer run cat tests, p068 comes in at 8000rpm (off), I made my scalar max fail at 520 instead of 512 (we will see if that does anything, it is for idle, but w.e idles smoother now)I have a performance cat/dp 3" exh. so that is probably why. generally I don't need a dtc to tell me my cat is bad, I can check by boost/vaccuum rear o2 if needed. So I think I pretty much ended the power engine reduce (knock on wood)

the map performance dtc I disabled, I run maf pretty much all the time and I just bought a new one.

bump for problem hopefully solved.

 

I got engine power reduced when I unpluged that sensor by the oil filter cap so I could change the oil filter and forgot to plug it back in.

 

I'm sure it would give some kind of indication if it was just that, haven't been down there for that to happen anyhow.

good news is it is gone, WOT pulls, everything, drove around for almost 2 hours today. fixed.



I did everything I stated above in hptuners, just for reference because someday this will be an old thread and someone will want to know what to do.