On higher mileage vehicles, an engine misfire may develop and/or the Check Engine Light may illuminate due to a failed ignition coil. It is not uncommon to replace all the coils when the first one fails in order to prevent return trips to the repair shop.
2005 Toyota Avalon Problem Reports
RepairPal Verified 2005 Toyota Avalon Problem Reports
The Check Engine Light may illuminate because a component of the oxygen sensor stops working. As a result the engine computer is unable to determine the proper ratio of air to fuel for the engine. Replacing the failed oxygen sensor should correct this concern.
A loss of power on the freeway may due to an internally leaking fuel pulsation dampener. This commonly occurs on higher mileage vehicles.
If the engine will not crank over, the most common problem is the starter. These will tend to go out at about 100,00-125,000 miles. Sometimes it is only the starter solenoid, but often the complete starter (including solenoid) needs to be replaced.
At higher mileages, (125,000-150,000) the automatic transmission may not shift correctly. This can be caused by the throttle position sensor being out of adjustment or a shift solenoid needing to be replaced. Typically the transmission does not need to be completely overhauled.
Toyota issued a recall on one of the connections in the steering shaft that was not welded properly, which could cause steering problems. This can be repaired free of charge at a Toyota dealership. The recall applies to only certain 2005 models only.