Having an issue with my transmission on my 1997 Honda Accord EX. It was not down shifting at all without manually shifting it ourselves so we replaced the shift and lock solenoids yesterday. Now it downshifts, just seems to be either slipping or late to the party, lol. It hits 3000 rpms, slips quickly to 4000 rpms then shifts. Throwing codes P0700 and P1718. Any suggestions?

 

OBDII AT codes for the 96/97 cars are not well translated, and often give an erroneous problem code that does not apply to the car.

P0700 is a generic "there is a problem with the transmission" code.
P1718, from ta quick google search states its a Transmission Temperature sensor. Your transmission does NOT have a temp sensor.

Look under your glove box door. You will see a TWO WIRE BLUE CONNECTOR.
Pull it down out of its holder and jumper the connector with a wire.
Turn the ignition switch to II(ON) and watch for blinking codes from the CEL and D4 light.

Record the code and post back here.

 

The only code it pulls that way is 41

 

Nothing from D4

 

And the code for the P1718 is "Communication circuit for automatic transmission".

 

41 Primary oxygen sensor heater. If there was a communications problem between ECU/TCU more than likely that would be D4 code 14 for the FAS wire.

EDIT: When you turn the car to ON before starting and all the dash warning lights come on, does the D4 light also come on?

 

It does normally, but not when we have the jumper in. I should mention that when this first started happening there was a loud bang, from the passenger side of the vehicle.

 

Engine health will affect how the transmission shifts.
Bad TPS, Thermo sensor, MAP, engine sensors will also affect how the transmission shifts.
If the ECU/TCU *think* the engine is doing one thing, the shift strategy will be changed to accomadate or try to work with the sensor inputs. If inputs are wrong the output will be wrong, including the shifting of the trans.
Check the wiring to your pre catalyst O2 and check the O2 itself.