I changed the stem on my two handle faucet in my tub and now when I turn on the hot water, water runs out of the handle on the cold water handle. I checked the o ring and tightened it the stem but it still is leaking. Any suggestions?

Are you saying hot water is actually coming out of the cold handle? Are you 100% sure you used a perfect match with the replacement stem?

No it was cold water coming out of the cold handle when I turned on the hot water. The stem was the same kind but I took it out and the distance from the washer retainer and the part that moves when it it screwed up as far as possible was longer on the new one so I put the old one back in with a new washer on the end and now it is not leaking. Thanks for answering my question.