I bought a 94 150 with the 4.9 a couple of months ago. Didn't run great. so far I have replaced the air temp sensor in the intake, the o2 sensor and a full tune up. since I replaced the 02 sensor I am having a new problem. The truck starts fine and runs fine in the morning. When I start it to leave work in the afternoon, it starts right up, but when I try to drive away, it stumbles and will stall if I try to excellerate. If I let it idle it runs fine. After about 2 min. it straitens out and runs fine the rest of the way home. No check engine light, no codes. Any Thoughts? Thanks Andy

 

Pull codes. Check tps, iac,ect, and look for vac leaks.