I had an oil change a while ago and about a week later I was stopped at a red light on a slight incline and my engine started idling like crazy. This happens every time I idle to a stop now and when I put it in reverse, but only after I've driven for about 15 or 20 minutes. Runs fine when cold. I've had the spark plugs done and cleaned the tb and maf sensor and nothing has changed, I've been all over forums and read so many possible solutions, just wondering if anyone knows exactly what's going on yet. Cuz I'm stumped

 

I also believe I get a faint smell of gas when it happens

 

The smell of gas makes me wonder if you have an injector stuck open

 

Did you do a scan for any pending codes? You also didn't tell us what truck you have.... or anything about it

 

My 99 f150 5.4 is doing the same thing. Seems like mine started doing it after I replaced dpfe sensor for 401 code

 

Whoops, 2007 5.4 FX4, haven't done a scan yet, 93,000 kms