Ford Explorer V6 goes out

Hello, I appreciate your time and help in advance.
I have a 1996 Ford Explorer with a V6 engine, and the problem is that the engine always stalls when I try to stop on a street. The moment I press the clutch, the engine stops instead of idling. It only happens in these situations when I want to stop the vehicle. Afterward, when accelerating and shifting gears, the engine RPMs drop until it idles when I press the clutch. The idle is uneven, and I've already replaced the IAC valve. I read that to check for a leak, the engine should stall when the IAC valve is electrically disconnected, but it doesn't, so there must be a leak, but I don't know where. Also, the speedometer isn't working, but it was like that before this problem started. Thank you very much in advance!

It's not necessary to disconnect the IAC valve; the engine will stall, though it might idle at high RPMs. You should have it checked with a scanner because this valve works in conjunction with the MAF or MAP sensor (air flow). Check the fuel pump pressure and the fuel filter. It might be stalling because it's either out of fuel or there's no spark to ignite the fuel. Regarding the speedometer, it could be a broken wire from the oxygen sensor, which is located in the transmission. If the transmission is functioning correctly, the problem could be with the instrument cluster. A common cause is dirty oxygen sensor sockets

Hahaha, the oxygen sensor has nothing to do with the speedometer, and it's definitely not located in the transmission. What a joke!

Sorry, it's the speed sensor

Hi, thank you very much for your reply. I'm sure it's not a lack of spark, since the moment it shuts off, I can restart the engine using the vehicle's momentum, and it starts perfectly fine and idles after that. It could be a fuel issue, but I'm not entirely sure.