Transmission codes p0743 and p0755

Good afternoon.

Does the transmission shift gears?
Also, it sounds like you have or may have a clogged catalytic converter. You can confirm by either removing the upstream O2 sensors and drive it or drop the front pipe and drive it and see if the rpm's goes higher than 3000.

let me check the codes.

Roy

I honestly do not know if it shifts gears anymore because it has such a horrible take off that it takes forever to even get going. But I would assume so because I have not gotten up faster than about twenty five mph and it did not whine like it did not shift to second gear.

Both secondary catalytic converters have been removed, one of them was very clogged up.

Okay, 743 is for the torque converter solenoid circuit either being open or shorted. the pan would have to be dropped to inspect the harness and do voltage tests to the solenoids to be sure. the solenoid needs to be checked for about five ohms across the terminals.

The 755 is for the shift motor for the four wheel drive system.

Roy

What about the catalytic converters up front by the engine?

Roy

Okay as far as 755 code I can understand that one and why. For the 743 code, could that circuit have been fried with a transmission wiring harness issue I had, melted to exhaust? but has been repaired.

It may have damaged the solenoid and the inside harness, yes.

The catalytic converters by the engine are still in place. I could not tell a difference in exhaust flow with the exterior catalytic converters removed. Would that solenoid damage cause the issue with no power at take off from standing still?

The torque convector will cause that if it is stuck applied. you need a full blown scan tool to monitor it.

As far as the catalytic converters, you cannot tell from amount of exhaust. you need to verify by a back pressure test.

Roy

How do you check the solenoid once it is removed to make sure it is still working correctly?

You need to ohm out the two terminals with an ohm meter.
You will also need to see if you have twelve volts on one of the wires to the solenoid with the key on.

Then you will need a scan tool to turn the solenoid on and off to be sure it can be activated.

Roy