veh losing power & is jumpy

I have a 1999 Toy Avalon XLS. The past 2 months it has been losing power and has been jumpy. It seems it is getting worse. As i drive on the highway and press on the gas, i notice that my gauge starts to go down and my car starts to slow down then all of a sudden it seems that it catches and takes off. It also shakes and jumps like it is going to stall but never does. Sometimes it does it when I start the car and put it in drive. If I put it in park and sit for a second it will stop but then start up again as I am driving. I have put 2 bottles of fule injection fluid and 1 bottle of dry gas so far and they did not work. Any other suggestions what this might be. Thanks :banghead:

Any 'check engine' codes? Get them read for free at parts stores and post back the numbers.

Offhand, sounds like you have a sticking idle air control (IAC) valve. These aren't usually cured with the typical injector cleaner use. The best way is to remove the intake tube, spray the cleaner into the valve inlet (usually a little hole in the bottom side of the throttle body) and let it soak. You can also remove the valve and clean it, but DO NOT IMMERSE THE WHOLE VALVE IN THE CLEANER. It is electrically operated, so the glues and insulating resins inside can be softened by the cleaner solvent...once they evaporate, they reharden and you have a frozen valve.

Other thoughts could be a sticking exhaust gas recirculation (EGR) valve or faulty throttle position sensor (TPS), but give the IAC cleaning a whirl first.

jdmccright,
Thanks for the quick response. The engine light had come on at one point and my husband plugged in his computer and I cant remember what the code was. We have been waiting to see if it would happen again so we can get the code again but no luck. I will def try your suggestions and let you know how I make out. Thanks Again. :)