98 intrepid engine swap, cranks great, engine starts hard, either fires and shuts down or runs only at idle 1000 rpm and shuts down with any throttle. Fuel to under hood connection.

what engine and did you use the same year engine and wiring harness?

rebuilt was in 2001 intrepid, went to original wiring harness, needed to switch one sensor to fit original harness was oval not round, and switch drivers side valve cover to match coolant line to warm air to pcv breather line returning to intake throttle body from Valve cover on newer engine(removed warming chamber). Didn't get any type of answer for a month so took to mechanic with better computer to read codes etc.; found Map sensor bad and sending low voltage to Throttle Positioning Sensor is what I was told by owner when he took to mechanic with better diagnostic equipment. Works fine now, although new (different) error codes have come up after old ones have been cleared. Owner has not informed me what the new ones are yet. is driving the car though. Is there a way to clear codes without scanner hooked to car on this car after correcting problem(s)?