I have a 2000 Toyota Avalon with 266000 mi. I just bought it and it ran beautifully when we got it. 2nd day it acted like fuel filter was stopped up. Then poof no problem for 12 days. Actually ran like a new car. now when you press on the accelerator it pops and you have to feather it to get it to go. If you stand on it, WOT, it runs very strong. but when you let off it feels like it's running out of fuel. Sometimes when you press on throttle it shakes violently, and SURPRISE! no codes no check engine no idiot lights. I cannot afford to throw parts at it. Where would you start. (It has a 3.0 VVT-i and it appears to have been well maintained.) I don't have a tester for the ODB, but have access to one. Lots of tools, but I quit working on cars in 1986 was a nissan tech with about 20yrs general exp and fully NIASE (not ASE) cert. So am marginally unfamiliar with newer cars systems. Any help would be Soooooo helpful. Lost and depressed. Thanks in advance.
Update: I got an idea, and it worked ... at least for now. I took off the battery cables and left them off for 10 min. Runs perfectly for now, actually better than it has since I have had the car??