Reduced Engine Power

[not_panda]

So, on my way home tonight as I rounded the last corner before my neighborhood, a "Reduced engine power" showed up in my DIC. Since I was in my neighborhood, I was able to chug on towards my house. I was unable to go over about 1000 rpm, and could not gain any speed. Once home I shut it off , and turned it back on, no luck. So I shut it off. Checked underneath for leaks, there was a couple drops of oil, but that's it. Checked my oil, still at a healthy level. But I went to turn it back on, and the message was gone. My gauge cluster is beyond screwed, so I can't tell if it was overheating at all, but I didn't get the "engine coolant hot" warning. Was this just some sort of fluke? Anybody have any ideas? My truck is an '04 yukon with the 5.3, at about 295,000 miles.

 

[Rocket Man]

Probably need to look for codes with a reader. My '02 Denali did that and it ended up being clogged cats. I guess when I shut it off, the particles would fall down and clear out and then after it was running again they would plug up. It got continually worse until I took it to a mechanic and he confirmed my suspicions.

 

[drakon543]

I cant remember what i was told about the cat issue mentioned but i remember it has something to do with thier heat. Once they heat up get choke off the exhaust and when they cool back down everything seems fine again. Anyway with 295,000 it could be numerous different issues. If you dont have a check engine light still on take it somewhere where they have a good quality scanner capable of reading tbe fault history.

 

[Rocket Man]

Exactly. Mine showed several codes that changed as things got continually worse (MAF sensor, Throttle Position Sensor, then finally multiple cylinder misfires after it got really choked. ) Reduced engine power could be caused by lots of things especially at this high mileage

 

[not_panda]

I've had the check engine light on for a while for a fuel pressure sensor. The thing is, I've replaced it 3 times and the light still would not go out. What that have any factor in this?

 

[drakon543]

Well the check engine lights wont always be 100% accurate. The ecm can only tell you where its seeing a problem. Your fuel pump could be getting weak and the ecm is seeing that problem at the pressure regulator. You should have the fault diagnosed at a shop then once you know what's causing it then you can fix it yourself. A problem with your fuel system might Be enough to trigger limp mode on your truck.

 

[not_panda]

And I had the cats replaced about 2 years ago, so I'm hoping that's not it either. I've been seeing a lot of stuff about the throttle position sensor. Do you guys think that it is? When I get the chance, I'm gonna go to autozone (if the truck can make it) and run the codes.

 

[not_panda]

Oh, and I had the fuel pump replaced around the same time as the cats.

 

[Rocket Man]

It's possible but like I said, you need to see the codes. The TPS isn't too expensive if I remember right so hopefully that's it.

 

[not_panda]

Truck was unable to move when I was gonna take it to autozone, so I just took a leap of faith and replaced the TPS. Started up just fine, no warnings, CEL went out. Drove it around for about 15 minutes, everything still good. So far so good. Thanks for all the input.