1999 Toyota 4Runner • 160,000 miles

The engine will start and remain idling, relatively smooth no clattering or load noise. However, the engine has trouble reving up and taking off. Once you mess around (with the gas peddle) long enough you can get it moving and then it seams to drink gas like crazy and be very under powered. It seams to me its a timing issue: timing chain or could it be the timing belt? I ask the question "which is it" because, one is a couple hundred dollars and the timing chain is roughly a thousand. I know the timing chain was replaced with in the last 40K miles. Some other issues, catalytic converter was stollen, o2 sensors? Can they effect engine timing or fuel to air mix? Could be drowning in fuel? It seam like its running rich. Any suggesting would be helpful.
February 19, 2013.

Scan for codes and check fuelpressure first

Feb 19, 2013.