Good evening folks. I have been working on my daughter's 1995 Cherokee Country 4.0 for about seven months. It died one day on the summer on a very hot afternoon. Below are the items replaced:

• Radiator
• Thermostat & housing
• Spark Plugs & Wires
• Ignition Coil
• Distributor Cap & button
• Throttle Position Sensor
• MAP Sensor
• Idle Air Control Valve
• Fuel Injectors

The issue is a rough idle at low RPM. With every new sensor or component replaced, it gets better, but still not fixed. It is now throwing code 27. I used a "noid" light to check signal and each injector is getting a signal. Any ideas on what to look at next?