k11c TPS and other problems

[thespooner]

Hello, a couple weeks ago while we checked the car for problems we noticed the TPS sensor wasn't working properly, it wasn't giving a smooth rpm change to the computer we connected it to, so I looked up online for a replacement. The thing is, our model's not the square one that I could only find online, it has a circular shape. I've been searching for somewhere to order it but I could not find a single place, can anyone suggest somewhere to look at? (I'm not from England) Also, I would be very thankful for some advice to how important is the TPS exactly, as the mechanic I was at told me that the car could run without it and I've been driving that way since that day. Another thing I've noticed that might be connected to that problem is that whenever I change from neutral into a gear, with the clutch all the way in (standing in one place) the idle rpm goes up a bit (~600 idle neutral rpm, ~850 into gear). I've talked to different mechanics about this and nobody seems to know what the cause might be, I'd be glad if someone could help me out some way as I am still very uneducated on that matter. Thank you