02' C70 possible ETM fault

[JexVaria]

Hello, bought a 02' Volvo c70. Fixing her up as I go, very happy over all.

I had the ETS light come on along with the CEL. Pulled the codes and got the following:
1100 - Outside Temperature Sensor
4020 - Fuel Tank Pressure Sensor
917F - Accelerator Pedal Position
9400 - Brake Pedal Sensor

First code was an easy fix, just put on a new Sensor.
Second code was remedied with replacing the EGR valve

Now I'm trying to figure out the last two.
I experience no loss of power when driving, there is that slight surge happening when idling. Brake lights and power brakes are working fine. I've been reading up on what it could cause these two issues. What are the odds of both sensors going out simultaneously? I've read where the it could be a faulty signal with the tps sensor. What would you guys suggest, going to replace both brake/acc sensors or the tps sensor. Any diagnostic ideas to further discern exact cause?

[JexVaria]

Little update, after some cleaning of the throttle body (and accidentally dropping it ), code 917f has vanished.

Code 9400 has been more troublesome. I got a used brake pedal position sensor (one going into the booster) from the junkyard. No change, code still pops up after change and clearing the codes. The data read out for the sensor in obdII seems stuck at 4.99v or 5v. I hooked up my multimeter to sensors (new and old) and the resistance value does change when sliding the rod in and out. When I plugged my multimeter into the sensor plug socket (going into the car) the data read out dropped to 4.69v with the multimeter set on continuity. I also tried resoldering the connections inside the old sensor, but the computer still reads the output at 5 volts. Any thoughts? Both the brake pedal position sensors seem to be working and I can change the obdII data readout for the sensor when I have my multimeter hooked up..