I have a 2013 5.0 that I just changed the water pump on. After that, it ran fine for a few minutes, then got progressively worse. It is now to the point that it starts normal, but then runs for about 3-5 seconds, with progressively lower RPM.

In changing the water pump, I also took off the throttle body and disconnected the MAF.

I double checked everything, and I don't see anything obviously wrong. There were codes P2195 and P2197 that made me think there was an issue with a vacuum leak. I took it apart and put it back together making sure everything was tight and cleared the codes.

I am now at the point of it only running for a few seconds. No check engine light, or codes that the Torque app on my phone can read.

If I disconnect the MAF or remove the air inlet tube from the air filter/MAF to the throttle body, it runs. Just with a lot of dinging and warnings on the dash related to stabilitrack, hill descent etc. I am assuming either of those triggers a limp home mode.

I am thinking it is either the MAF, the wiring connector to it, or a vacuum leak, but it is tough to find a vacuum leak when it either doesn't run, or runs rough because stuff is disconnected.

Has anyone else run into this or have any ideas?

 

I forgot to mention, I also tried disconnecting the battery for about half an hour, no help.

 

After some more troubleshooting with ForScan, it looks like it may be related to the TPB/Throttle body. I am not seeing any information for the the throttle position when it is running. I have ordered a new throttle body, hopefully that fixes it.

 

An update, all better now. I got the new throttle body, it would idle, but not run if I revved it up at all. I replaced the MAF and it works great now. I am not sure if the throttle body was part of the problem or not. I may have mad a mistake in ForScan looking at the throttle position sensor data.

The fact that it would run with the MAF unplugged should have been a clue to start there, especially since it is a cheaper part. Oh well, still up and running again.

 

I see nobody replied. But thanks for the update. The information helps others. My '14, 5.0 would stall at stop lights with low idle. Ran fine otherwise with no codes.
Changed the MAF, problem solved.