Hey everyone,
I have a 1999 Toyota Avalon with a 1MZ-FE engine and 370k miles. Recently, my car has been losing power especially uphill dropping to 20-25 mph on a 12% grade. It also jerks when coasting at 60-65 mph around 2000-2200 rpm.
Here is what I have done so far:
- Changed spark plugs (Denso) and wires (NGK)
- Replaced one O2 sensor and EGR sensor (had codes)
- Changed fuel filter and pump
- Measured fuel pressure
- Replaced timing belt, water pump, seals (AISIN Kit), and thermostat
- Went to Toyota dealer for diagnostics – no help, no codes
I drive 70-80 miles daily, so any in-depth work has to be on weekends. I also searched about this problem on this https://www.cargurus.com/Cars/Discussion-t17726_cpq/_ds540276 but I could not found something helpful. Any suggestions on what to check next? Could it be the catalytic converter or a vacuum leak? Thanks in advance!
Looking forward to your advice! 
Steve