I have an 01 ranger with 85k on it and a couple of months ago it began to rev itself atleast 500 rpm too high in each gear and it runs 2500 rpm with no gas in park. Gas mileage has gone down about 1.5 mpg. I think it might be my idle limiter or rev limiter is somehow running too high. I had a Jet chip in it but took it out cause i thought that was the problem. It helped a little but didnt fix the problem. If anyone could tell me what the problem might be and how much it would be to fix it that would be appreciated. ALso i'd kinda like to put the chip back in cause i miss it alot so if anyone knows if it would be ok to put it back in that would be cool too. thanks guys

 

It sounds like the IAC valve is stuck open.