You need to do an injector balance test. You said in your first post that

as soon as you added the Lucas Injector cleaner that the missfire code

appeared. I would say one or more of them are partially clogged up. If you

have access or know someone that has a good scanner to actuate the

injector balance test to see how much pressure each injector drops. Do that

first before spending any more money on parts that don't need replacing, as i know how that gets real pricey and aggravating.