nvcc preprocessing failed compile error

I installed CUDA9.1 with driver -version 387.34 on Ubuntu 16.04
I ran very simple example code, but I met this compile error.
Although I searched for solving this problem, there are only past information about 1 years ago.
They were almost related in CUDA7.5 and CUDA8, but I have CUDA9.1

How can I solve this problem?
this below code is my error message.

CompileError: nvcc preprocessing of /tmp/tmp1ni691lp.cu failed
[command: nvcc --preprocess -arch sm_61 -I/usr/local/lib/python3.5/dist-packages/pycuda/cuda /tmp/tmp1ni691lp.cu --compiler-options -P]
[stderr:
b"nvcc fatal   : Value 'sm_61' is not defined for option 'gpu-architecture'\n"]

I also made PATH in ~/.bashrc

export PATH=/usr/local/cuda-9.1/bin${PATH:+:${PATH}}
export LD_LIBRARY_PATH=/usr/local/cuda-9.1/lib64\{LD_LIBRARY_PATH:+:${$LIBRARY_PATH}}

Your installation of pycuda is apparently picking up some version of CUDA on your system older than 8.0

to confirm this, search for all instances of nvcc on your system, eg.

sudo find / -name nvcc

Thanks for help.

My result of $sudo find / -name nvcc

/usr/local/cuda-9.1/bin/nvcc
/usr/bin/nvcc
/usr/lib/nvidia-cuda-toolkit/bin/nvcc
find: ‘/run/user/1000/gvfs’: Permission denied

So you have multiple instances of nvcc

You’ll need to clean out old installs that you don’t intend to use.

How can I find old version?
Can I uninstall only that one? How ?

And although I only installed 9.1, why is it installed multiply?

sudo apt-get autoremove --purge cuda

Could I do this?