Get the codes checked first. More than likely the convertor is shot because of the oil burning (if it's not leaking it's being burned), as well as the O2 sensor(s).
Have a compression test done on the engine to see if there is a weak cylinder (rings, or valves).
The rattling is either the valve adjustment (Toyota uses shims), or possibly a timing chain, or a problem with the VVTi or the PCM (excessive ignition advance). Could also be some bad gasoline, but it should run fine on 87 octane.
You want to get the rattle fixed ASAP, as this can cause severe engine damage.
Thursday, September 4th, 2008 AT 5:41 AM