I have a 2015 Yukon Denali with the 6.2 and the car seems to drive normal, however whenever the accelerator is really pushed at all its as if nothing happens at all. It is as if there is almost no horsepower. The engine does rev up high but slowly and seems to shift normally. I have an OB2 and the torque app and looks like fuel pressure is normal the throttle all seems normal the only thing that seems not normal is the HP reading. Im not sure if that is even accurate but the highest I got it to go was maybe 50 HP at 3500 RPM. Also the car has no codes at all and no check engine or anything out of the ordinary.
Loss of Horse-power with no codes
- Thread starter p1zaul
- Start date
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Bigkevschopshop
Full Access Member
Almost sounds like limp mode but would illuminate a code for sure... Could be a sensor starting to fail, something like MAF sensor can do weird things, plugged air filter or exhaust can do it also. It makes me think that whatever is wrong is not long term enough for a CEL to throw, maybe a few more run and restarts would make it throw a code. I know a soft code would be present right now probably so if you hit a shop for a scan they may see something. To save money, I would start with the basics, check oil level, air filter, etc and go from there. Visual inspection of the electrical plugs etc, make sure they are plugged in etc.
Thanks I will check the air filter, appointments are booked weeks out and have been driving like this for two weeks now. It seems pretty dangerous as you can really not pull out in front of anyone it is so slow. Shop thinks possible catalytic converter is clogged. Not sure how I can tell.
How many miles on it? Has it ever used oil in between changes, and what is your oil change interval? Have you ever cleaned the throttle body? Also, did you get gas at a new station recently? Maybe some water in the fuel?
Edit: I would agree is sounds like plugged cats, but could very well be a MAF sensor as well. I had a flaky MAF sensor in my 2001 impala and when it acted up, it was a real pooch......sometimes couldn't get out of my own way.
Edit: I would agree is sounds like plugged cats, but could very well be a MAF sensor as well. I had a flaky MAF sensor in my 2001 impala and when it acted up, it was a real pooch......sometimes couldn't get out of my own way.
So it's got just offer 100k, I don't think it's burning any oil and I change every 5k full synthetic myself. Gas has been pretty much just Costco and I have recently added some techron. I took a look at the throttle looks good and also sprayed that aerosol sea foam in there. No difference at all in the last few weeks.
tooleyondeck
Full Access Member
I concur with the other members here, check your MAF and throttle body and give them a good cleaning. Keep us updated when you get it figured out. Hopefully it is something simple.
Bigkevschopshop
Full Access Member
Easy test for Mass airflow sensor, just get a cheap one from the local parts store and replace it, if it doesn't work take it back.
