engine code

Mk3 Astra TPS low volt (22) code and hitching in low revs Had this happen a few times and replaced the TPS each time but it keeps comming back not sure why gonna go chase the wires a bit. Each time I replace the TPS the hitching stops for a while. We also had an issue with the fueling on...

I asked this a while ago, and no one could answer. Someone said, it's easy to tell if I can see it. So here's a photo. It's a 1.4.

Bear with me cause i'm used to VW's and i'm a bit of a noob at this.... when checking my oil earlier i noticed the engine code stamped on the block was X16SZR. but i thought all the X prefixes were to denote a 16 valve, and C prefix denoted 8 valves, when mine is just an 8v premier... ???