Help

[Hotsauce80]

Good morning, I like many have a rough idle and now suffering poor mpg. I have done the MAF cleaning, new PCV, new fuel rail pressure sensor, new intake gaskets and replaced both up stream o2 sensors. (Also did both front hun bearings ) rides like a dream now. Anyway , as I drove my average in the info center climbs and levels out, but when I stop at a light or idle for any amount of time I can watch my numbers drop quickly . This morning I averaged 16.4. Stopped at a light and when it turned green I was at 11.6. What in the hell is going on?

 

[plasticseng]

Is the check engine light on?

 

[Stick4503]

Your short term MPG is going to drop when you are stopped. The computer averages the amount of fuel used with the miles traveled to get MPG. If you are stopped with the engine running you are still using fuel but not gaining miles driven so the computer sees less miles gained for the fuel being used. Those are rough calculations, if you want to find MPG you need to do it by the tank or over a few tanks.

 

[drdoom]

Question: how often are you resetting the MPG readout?

 

[Hotsauce80]

Thanks for the replies. No check engine light and only reset after filling. I understand it will hunt for an average soon after resetting. I also understand I will loose on average if I idle a lot or floor it all the time. It never acted like this before and I always averaged 17 mpg. It never dropped as quickly as it is.