Originally Posted by Soppy
Check your ignition timing. The tan or brown wire behind the distributor has to be disconnected to properly set the timing. A plugged cat or bad ECU temp sensor could also be the culprit.
Soppy is on the right track when he says the timing is not set correctly. You should have an emissions label with the tune up specs on it which will should point out where the wire connector is to disable the electronic controlled timing module so you can set the timing to specs using a timing light. This is absolutely necessary to set the timing correctly.
Note this will trip the check engine lamp on. When you are done setting the timing shut the engine off, reconnect the wire and disconnect the ground cable from the battery for a half minute or so to clear the system.