Hi scotty could really use your help i have a 2006 gmc envoy denali been driving fine sense i got it but all of a sudden today bringing my wife to work go to start it up and it makes a weird sound and goes away well while driving down the road every time i hit 1000 rpm's the car jerks and then goes on to drive fine til i got to stop and start driving again the same jerks at 1000 rpm's there is no lights on the dash but did hook up a code scanner and i should mention its a cheap 1 sometimes it dont give me all the codes but it did give me 2 that are P0171 and P0174 would these cause the jerking or am i looking at a transmission problem im dreading hoping its not the transmission so any help would be greatly appreciated thanks for your time.
mileage please.
About 115k 5.3l v8
Not flex fuel and its 4x4 to
Don't be a parts changer. Diagnose the problem.
The codes indicate a lean condition (too much air in the mixture)
Standard troubleshooting is to check for vacuum leaks and measure fuel pressure.
Scotty has videos about all this stuff on his Youtube channel.
Please specify which engine you have and whether it's flex fuel.
The jerking sounds like a transmission problem to me, but a tranny shop would have to diagnose that.
The intake manifold gaskets were a weak spot on those engines, so focus on looking for vacuum leaks around there. Fortunately, changing the gasket with an improved one, is a relatively easy and inexpensive job. There are many videos showing how to do it on the internet.
Google gave this answer, so it must be right. Just change parts in that order.
Not.
Codes most likely indicate a lean condition, I would not worry about the transmission at this point. Check the basics first.
