Just put my tranny in and this problem never happened before my tranny was out.
I would start in 1st gear, then shift to 2nd, then 3rd(where it fells like the car is off and the CEL comes on). I would have to drop it back to 2nd gear, then shift to 3rd which would be fine. I pulled the code it was the oxygen sensor. I cleaned it off cause it was filthy black. It did the buckin thing again in low rpm. What is going on?? I apologize if you cant understand this....trying to type this work

Before I my tranny went out I was getting a CEL9 (no1 cylinder position sensor). Did not pop up when pulling codes

 

Well I don't see how this could be related to the removal of your tranny. Do you have another o2 sensor you can try?

 

make sure your battery ground is good as you have to take it out to remove the trans.

 

Yeah, I know it doesnt have to do with my tranny. This happen right after I put it in. I replaced my OEM o2 with a bosch. I just dont get it

 

bump