Overheating/starting issue

[Jprater7870]

I have a 1996 explorer XLT 4.0 4x4. I just bought it and it has an issue where it won't start after it warms up and sits for a few minutes. It was showing code 0420. I cleaned iac, and changed maf. Once it starts tho It runs great. Well until 2 days ago. This is unrelated. It started overheating. I changed thermostat yesterday, and its still overheating. Any help would be greatly appreciated. I'm not very mechanically inclined,so I'm at a loss

 

[1998Exp]

I have a 1996 explorer XLT 4.0 4x4. I just bought it and it has an issue where it won't start after it warms up and sits for a few minutes. It was showing code 0420. I cleaned iac, and changed maf. Once it starts tho It runs great. Well until 2 days ago. This is unrelated. It started overheating. I changed thermostat yesterday, and its still overheating. Any help would be greatly appreciated. I'm not very mechanically inclined,so I'm at a loss

A common source of hard starting of a warmed-up engine is a defective coolant temperature sensor (or its wiring).
Code 0420 is for "catalyst system efficiency below threshold - bank 1." Sometimes it can be cured by replacing the downstream oxygen sensor on that bank. Another possibility is a leak in the exhaust system. Otherwise, it indicates what it says - insufficient catalytic efficiency, and may require replacement of the catalytic converter. Before venturing in that direction I would check the general condition of the engine. Excessive oil burning or prolonged misfiring will damage the converter. Also, if it's still overheating after replacing the thermostat I would suspect exhaust gas in the cooling system.

 

[Mordecai]

I have a 1996 explorer XLT 4.0 4x4. I just bought it and it has an issue where it won't start after it warms up and sits for a few minutes. It was showing code 0420. I cleaned iac, and changed maf. Once it starts tho It runs great. Well until 2 days ago. This is unrelated. It started overheating. I changed thermostat yesterday, and its still overheating. Any help would be greatly appreciated. I'm not very mechanically inclined,so I'm at a loss

I had the same issue with my explorer, same year same engine, sort of a hesitation to stay on after its warmed up. I did replace the ECT sensor and IAC recently per advice from MBrooks420, seems to start well now even when its warmed up all the way. The sensor is really easy to get to, all you need is a flat head and a 3/4 wrench for the sensor its directly under the throttle body. Good luck!

 

[Jprater7870]

I have a 1996 explorer XLT 4.0 4x4. I just bought it and it has an issue where it won't start after it warms up and sits for a few minutes. It was showing code 0420. I cleaned iac, and changed maf. Once it starts tho It runs great. Well until 2 days ago. This is unrelated. It started overheating. I changed thermostat yesterday, and its still overheating. Any help would be greatly appreciated. I'm not very mechanically inclined,so I'm at a loss

Ok thank you both. I'll buy a new ect sensor today. About the exhaust leaking into the cooling syste. How does that happen,and what are some solution(s)

 

[donalds]

How does that happen,and what are some solution(s)

A bad head gasket will cause that

 

[Jprater7870]

So I changed the coolant Temperature Sensor and my overheating problem was resolved. Don't know about the start issue yet. It happens so randomly that I can't really test it. But thanks so much for the help. You really saved my ass.