Help please! Renault Clio limp mode

Hi all

So, I was getting my car ready for sale a couple of weeks back and I began by changing the oil, oil filter, new battery and anti freeze.
My father helped me and told me to take out the HT leads prior to changing the oil, so that we could turn the engine over without powering it, to drain the oil. (I inspected the leads today and 3/4 have very small bits of white gunk? Also when I initially pulled them out, the first one was almost stuck in)
After changing all this, I had gone to start up my car and it went into limp mode. (Wouldn't rev past 3-4000 rpm, lost all power etc.)
I turned it off straight away, turned it back on quickly and it started fine and revved out freely!
After turning the car off again, I went to see if the problem would reoccur by restarting it and it did, while bringing up 3 dashboard lights;

Below I've pointed out what lights are coming up on the dashboard, I've sourced this from - http://www.drivingtesttips.biz/renau...s-symbols.html -

TOXIC FUME WARNING LIGHT

AIR BAG WARNING LIGHT

ELECTRONIC FAULT WARNING

DASHBOARD WARNING LIGHT


Basically, if I turn on the ignition on without turning the engine over, the Electronic fault warning light will appear, then when I turn the engine on, it wont let me rev over 4000 rpm.
But if I turn the engine over straight away, the Electronic fault warning light doesn't come on and I'm allowed to rev the engine freely.

The Toxic fume light, air bag warning light and dashboard warning light stay on.

I've taken it for a diagnostic test but they didn't say what codes had come up, therefore not letting me know what the problem is!
They mentioned it could either be the throttle body or the throttle pedal sensor (?).

Any help would be severely appreciated and go a long way! I'm 20, skint and need this car gone haha :(
I've tried being as thorough as possible, sorry for all the writing!
Thanks in advance!