Passing gear doesn't work..
 

Normally would shift from 4th to 2nd at 60 mph but now will only go to 3rd.No loose wires and just had headers installed.Need educated.The performance shop messed with my Diablo a little.

Hello, any help would be appreciated.Is this a PCM problem.

Thats unusual...I can't think of what would cause the trans to not go into second gear. The car goes into 2nd with no problem under normal acceleration?

i had this problem before. a shift kit and and pcm would fix that. I would think pcm tuning would do it on its on though

i had this problem before. a shift kit and and pcm would fix that. I would think pcm tuning would do it on its own though

So what did they do? Change the trans tables? Maybe?

Boy I didn't see that you said the shop used the DS on your current program. If they modified your shift tables like jxaxsxoxn stated they might have changed the kickdown tables. If so it may not have even been intentional. I know when I first tried to mod my shift tables I messed everyting up on the downshit and had close to the same problem.