disconnectiong battery

My check oil light keeps coming on once and a while so I disconnect the battery and recocnnect it and it usually shuts it off. However a couple weeks after doing this it started to rev up when I pushed the clutch in to shift. I took it back to where I bought it and they put a different idle air control valve on it. However it started doing it again and the guys at the shop told me it was because I was disconnecting my battery and it was messing up the computer. Anyone ever herd of not being able to disconnect the battery? How are you supposed to change it without messing up the computer?? Thanks for the help O yeah it is a 94 ranger with the 3.0 V6

My check oil light keeps coming on once and a while so I disconnect the battery and recocnnect it and it usually shuts it off. However a couple weeks after doing this it started to rev up when I pushed the clutch in to shift. I took it back to where I bought it and they put a different idle air control valve on it. However it started doing it again and the guys at the shop told me it was because I was disconnecting my battery and it was messing up the computer. Anyone ever herd of not being able to disconnect the battery? How are you supposed to change it without messing up the computer?? Thanks for the help O yeah it is a 94 ranger with the 3.0 V6

I've swapped a Speed Density to MAF ECC and have no issues like that you've described. The ECC was used and was sent to me from California. There are certain values that your ECC remembers, but they should return to normal after a certain peroid of time. Usually, it isn't even anything to make a difference like that. If it's consistent, and doesn't get any better, something else is wrong. I've installed several car audio systems and have had the battery unhooked for a long peroid of time. All ran normally after installation. Sometimes, vacuum leaks, or your engine running not rich enough will cause a lean condition. Have you noticed any change in your MPG? Also, grey spark plugs are a good indicator of a lean running condition...