94 van-b150 v6 3.9 engine light and hesitation after thermostat opens

here goes-long story. v6 3.9 engine van b-150. engine light comes on after it warms up---engine runs rough and misses---at acceleration it bogs down. If I press on break it brings the engine back. I just had the transmission rebuilt and that wasn't the problem. In the beginning the code read overdrive problem, yet the van is a 3 speed-no overdrive and the other o2 sensor. I replaced the o2 sensor also. I'm in the process of replacing the coputer coolant sensor. Any ideas after this? I will get a read out then go from there...

Thanks

What is your vacuum reading at idle both while cold and after it's warmed up with the problem happening?

What is your vacuum reading at idle both while cold and after it's warmed up with the problem happening?
Hi-I haven't checked the vacuum as of yet. I'm placing a temperature sending in it tomorrow morning. That was the next issue I was going to adress...A vacuum leak.

I suspect that you're going to find an intake manifold vacuum leak. A quick way to check for that is to spray carb cleaner along the gasket and listen for a change in engine pitch or RPMs.

just wanted to post a response as to help other people who had my problem and now its fixed. I'm a half mechanic when it comes to troubles. I went to a mechanic who was recommended. Got a read out on computer transmission overdrive and o2 sensor. I thought to myself its a 3 speed--no overdrive. Yet trusted mechanic and he told me it was the transmission. Had it rebuilt and and still got engine light. o2 sensor. He should have told me to start with that. I need my van its my work van.
I put in a new o2 sensor and a tempature sending unit. The tempature sending unit needed replaced. It was corroded and now it reads proper tempature at 1/4 on the gauge. Still I had my missing and jumping. I got a three aaas catalog in the mail and it listed all the certified mechanics in my area. I called one on the phone who was close by and I could tell he was enthusiastic and gave him the specs on my troubles. Also I had heard a few times heard a clicking in the front dash board and mentioned tha to him. A short somewhere telling the computer box it was shorted somewhere---sure enough---this mechic found it in about an hours time. A corroded wire in the wire harness just above the o2 sensor near the transmission. He now has my business for sure...anyway--good luck on your endeavors...