Hey guys. I'm having an issue at 45mph/1400rpms where my engine revs continuously between 1400 and 1600. The only time it does it is between 44 and 46mph. Last time I checked for codes, there were none (engine related anyway) and I've replaced the tps and cleaned the maf sensor. Any ideas?

Thanks in advance, and if you need any more info just ask.
Steve

 

drive faster

 

might be slipping out of over drive. try putting your truck in D instead of OD and drive it up to 50mph and see if it still does it