03 Ex 4.0L questions

[NotAFordGuy]

I've stated what I've replaced in my quest to solve the cylinder #5 misfire in other posts. After cleaning the IAC, replacing plugs and wires, replacing coil pack, replacing MAF sensor, replacing EGR valve, replacing fuel filter, and replacing #5 fuel injector. There's still no change in engine performance. My SES light is on constantly with a cylinder 5 misfire code and nothing more. There's a strong smell of exhaust on the driver's side when driving on the highway with the windows cracked. You can hear the misfire which causes faulty shifting in the transmission. BUT, when my SES light starts flashing, the engine and transmission run smooth and fine. When the SES stops flashing and stays on, the misfire and sloppy shifting are present. After a trip, there's a strong smell of raw fuel when we shut the engine off. Thank you for any help in advance. I'm not understanding the difference in performance when the SES light is on vs. flashing?

 

[Number4]

Have you done a compression check? (Leak down test as well.)

 

[Mr. Alligator]

I've stated what I've replaced in my quest to solve the cylinder #5 misfire in other posts. After cleaning the IAC, replacing plugs and wires, replacing coil pack, replacing MAF sensor, replacing EGR valve, replacing fuel filter, and replacing #5 fuel injector. There's still no change in engine performance. My SES light is on constantly with a cylinder 5 misfire code and nothing more. There's a strong smell of exhaust on the driver's side when driving on the highway with the windows cracked. You can hear the misfire which causes faulty shifting in the transmission. BUT, when my SES light starts flashing, the engine and transmission run smooth and fine. When the SES stops flashing and stays on, the misfire and sloppy shifting are present. After a trip, there's a strong smell of raw fuel when we shut the engine off. Thank you for any help in advance. I'm not understanding the difference in performance when the SES light is on vs. flashing?

Could it be your PCM? Might explain the SES light issue. Seems like these are last the resort to diagnose and never diagnose themselves. I only get to figuring out these issues after going through everything else.

Good luck with this!

Mr. Alligator
1997 XLT SOHC

 

[NotAFordGuy]

I've been suspicious of the PCM this entire time. How often do they go bad in our Explorers? I see many listings on eBay for them. I've had to replace two PCMs in two Dodge and Jeep vehicles before. The seller I would normally purchase a PCM from doesn't have any Explorer PCMs in stock. Do I have to have the PCM flashed to my VIN, part #, and mileage, like other auto makers require? Or do Ford PCMs come compatible with any other 3rd Gen Ex? Thank you for any help. Also, what is the correct procedure for resetting my PCM in this Explorer?

 

[Mr. Alligator]

I've been suspicious of the PCM this entire time. How often do they go bad in our Explorers? I see many listings on eBay for them. I've had to replace two PCMs in two Dodge and Jeep vehicles before. The seller I would normally purchase a PCM from doesn't have any Explorer PCMs in stock. Do I have to have the PCM flashed to my VIN, part #, and mileage, like other auto makers require? Or do Ford PCMs come compatible with any other 3rd Gen Ex? Thank you for any help. Also, what is the correct procedure for resetting my PCM in this Explorer?

I think you need a PCM specific to your year and model. Maybe even for your VIN number. Ford does not have to flash them. I have only replaced the PCM once for my vehicle, at about 390,000. As I recall, you should be able to order one that is plug-n-play.

I certainly would not purchase one that is made for another vehicle.

Good luck!

Mr. Alligator