Toyota Prius: injector failure.....

Carl Powell wrote: 

Check to see that you had the LSC 40E "Engine Compartment Seal"
campaign done on your US 2004. This limited service campaign for the
2004 was to add a bit of weatherstripping under the hood near the
windshield, to prevent water from getting into places in the engine
compartment that water shouldn't be getting into... Repair is free, no
mileage limitation, but must be done prior to July 31, 2007.

Also, have you had the SSC 50P campaign done? Depending on your VIN,
it's either only an ECU firmware upgrade, or it may also put a
dielectric grease onto a wire to prevent water from causing problems.
This was considered a safety recall, so again free repair, but no
limitation on time.

Finally, you've been using the correct grade of gasoline, right? Too
high octane gasoline is known to cause check engine lights for a
cylinder misfire.

Carl Powell wrote: 

Check to see that you had the LSC 40E "Engine Compartment Seal"
campaign done on your US 2004. This limited service campaign for the
2004 was to add a bit of weatherstripping under the hood near the
windshield, to prevent water from getting into places in the engine
compartment that water shouldn't be getting into... Repair is free, no
mileage limitation, but must be done prior to July 31, 2007.

Also, have you had the SSC 50P campaign done? Depending on your VIN,
it's either only an ECU firmware upgrade, or it may also put a
dielectric grease onto a wire to prevent water from causing problems.
This was considered a safety recall, so again free repair, but no
limitation on time.

Finally, you've been using the correct grade of gasoline, right? Too
high octane gasoline is known to cause check engine lights for a
cylinder misfire.