[severm]

I have recently lost mpg from around 22 down to 18-19. I also have noticed the tranny shifting out of overdrive on the same hill at the same speed whereas it did not do so before. I have done some coolant bypasses on the TB and the transmission and a cooler tstat. Nothing else that I can think of that might cause this. Did the plug change recently at 64k and cleaned the TB but no change. Any ideas/solutions would be appreciated. I hate things like this I can't figure out on my own. Thanks for any and all replies. Mike

 

[jhughes3281]

Could it be as simple as running the a/c and the engine trying to compensate. I have noticed my truck shifting a bit more on hills, but it has been about 95-100 degrees here for the past few weeks when it was 80-85.

 

[dubie2003]

Have you done the TB relearn? It may be worth a shot.

 

[severm]

It has been HOT!! and the AC has been on. That may be the problem. How do I conduct the TB relearn?

 

[colin123]

How to:ECU Reset,Throttle & Accelerator Position Learning - Nissan Titan Forum

when you cleaned the tb you may have moved the butterfly and that will throw off the throttle pos settings

 

[severm]

Colin123, THAT is exactly what I was looking for. I have tried the steps to reset the mpg to no avail. Don't know what is wrong--probably me. I will try the other procedures and see what happens. Thanks a bunch. I will let you know if it works.

 

[colin123]

no prob, i have that page book marked on my favorites lol. good luck

 

[hyperx2002]

has anyone else tried this to remedy rapid on-set poor MPG???

 

[severm]

FINALLY!!! I was able to do the computer reset for mpg ONLY AFTER performing the other relearn/resets for TBS etc. I could not do the ECU reset before this for some reason. When I completed the others, the ECU reset worked like a charm the first time. Weird!!! Will see how it works. I just filled up this morning and am down to 18 mpg or less from 22 mpg previously. Maybe this will fix the situation. Thanks again Colen123. I too, have now bookmarked this page. I would highly recommend all do this. You can either print it out for use or, make notes like i did to carry around when needed.