i have a cammed z28 its got level 2 trans from proforma.4.10s 3600 yank.im making about 370 at the wheels probelem is sometime or most of time from dead stop in drive or od if floored it will only spin real quick and then shift and bog the car down to about 2000 rpms.whats the problem.i do have tps code po121 and low maf po120.help me out.also did bump stop mod tps code been on ever since

 

Your issue is with the PO121 and the MAF! And I would stop flooring the car and letting it do that until the issue is corrected , The MAF and the TPS issue can and will kill your trans, The PCM is getting the wrong information from them which is critical and telling the trans to do the wrong things at the wrong time, Again you can and will damage the trans its even possible if you done this many times you could have already done damage.
In fact I wouldn't even drive the car if at all possible till its corrected you need to goto a tuning shop asap.

 

ok sound good because i dont want to loss my warrenty with u guys.ok will call tuner tommorrow and see what they can do.

 

i dont understand i dont remember this happening with stock trans is it because of gear change.replaced 3.23 with 4.10 when i bought stage 2.

 

Did you have your computer retuned for the gear change? With the codes you have and if you did not have the computer recalibrated, that can totally be the issue with the way your trans is shifting. Get it corrected ASAP.

 

no i did not have gear change done what is i went to get tuned for gear change they put tune in and it still acted the same so they took tune out and told me trans was bad i got new trans and its the same and i dont want to drive car.

 

They need to set the tune for the gears then address the PO 120 and 121 which is the source of the issue, The PCM relys heavily on these two inputs to operate the trans and other things properly