TC question - NEED ADVICE!!!

[Blk Bird]

i've been having some trouble with my Yank 3500 tc as of late. normally, i'll only set off my SES light when driving long distance trips, and after cruising for at least 20-30 min, as the car would subsequently shift kinda hard in 1st and 2nd gears. now however, I set off my SES when driving down the road for 5 min, also noticing the subsequent hard shifts in 1st and 2nd gears. recently, i upgraded my car from 3.42s to 3.73s and have also installed headers. are these recent mods the reason for the change in shifting and the SES light? and if so, what do I do about the constant SES light being on?
i've tried to call Yank directly to ask them about it, but i'm having trouble getting through, and they haven't responded to my email (sidenote, anyone know if they've gone out of biz or something?)
thanks!

neil O>

[Turbo V6 Camaro]

Originally posted by Blk Bird:
i've been having some trouble with my Yank 3500 tc as of late. normally, i'll only set off my SES light when driving long distance trips, and after cruising for at least 20-30 min, as the car would subsequently shift kinda hard in 1st and 2nd gears. now however, I set off my SES when driving down the road for 5 min, also noticing the subsequent hard shifts in 1st and 2nd gears. recently, i upgraded my car from 3.42s to 3.73s and have also installed headers. are these recent mods the reason for the change in shifting and the SES light? and if so, what do I do about the constant SES light being on?
i've tried to call Yank directly to ask them about it, but i'm having trouble getting through, and they haven't responded to my email (sidenote, anyone know if they've gone out of biz or something?)
thanks!

neil O>

3.42 to 3.73 would change mess up your shift points some that could be it

[FlyBoy9994]

Sounds like the PCM is confused due to the new gears... Did you have any problems when you upgraded to the 3.42 gears??

Not sure about 1999 but you might either have to re-program your PCM or get one from a Y87 car.. Also, I'm not sure how the TC figures into all of this but I'm pretty sure it's related to the new gears..

[Notoriousdom]

TC might throw the missfire code. It detects different load with a different weight TC. Check the code.

Gears won't throw SES light.

[Dan Vincent]

It's your valvebody... Do a search on P1870.

[bu-bye]

moving to drivetrain forum....