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....

[Blk Bird]

no, i never had any issues when i upgraded to the 3.42s, and i know that i can't throw a code just b/c of a gear upgrade. however, getting a Y87 programmed PCM will do me no good as thats for 3.42s, not 3.73s. i also know that the tc will throw a code, however, its just throwing the code under different circumstances than it has always done in the past. as for the valvebody - P1870... what exactly does that mean? i don't know much about valvebodies - and if it is that, is there something i can do to solve my problem, or just know that thats whats causing it?
thanks for the help.

[snatch]

I actually just had my converter $h!t the bed on me, I kept getting a SES light, and I thought it was my O2 sensors, but the tranny shop reset the computer and I have been driving ALL day and it hasnt come back.
So I think it was because of the TC slipping. How was the upgrade form 3.42's to 3.73's? Any noticable difference?
Shane

[Blk Bird]

no difference in SES light comin on w/ the upgrade to 3.42s... as far as guessing which code the light is throwing, i had a diagnostic about a month ago and it threw an O2 sensor and cat (i replaced both when i installed the headers)... and the light came on simultaneous w/ the hard shifting that i normally get when the tc throws the tranny slippage code, so i have a pretty good suspicion that the code is due to the tc...