HELP po741
 

Anyone ever have issues or fixed code PO741? Its for torque converter clutch circuit performance, causing no converter lock up which in due time causing trans temp to rise to 230-240°+ when driving over 50mph more than a couple miles at a time. It'll shift fine and run cool on back roads if im under 50mph, anything more for longer periods of time, it doesn't get back into overdrive. I've changed trans fluid/filter, bypassed the thermal block and new TCC solenoid with no luck. Getting ready to install 4.88 gears but wanting to fix this prior so im not running HIGH rpms on the road, while its already at 28-3k at 60mph with 39s and 3.73s. I do have a new Torque converter to install if it comes down to it, just trying to avoid dropping the trans if it ends up being something simple.

Not sure but I'm betting the trans is coming out. You might as well rebuild it then. You've just spent the vast majority of the labor in the R&I anyway.