HELP!! Audi A3 engine shaking

[Gino21]

Hi its nice to meet you all, im new to this site and i hope some one hear has more knwolege and expierience that me so basicly i bought a 2008 Audi a3 1.6 pettrol (the 5 door version) when i was buying the car the previouse owener told me he has the trottle changed but the engain light was on i thought i thought that all i have to do is readapt it and clear the foulty codes as i did the next day the problem continued the car engain can be felt shaking as if the car was doing incomplet combastion on cold engain its not that bad and is very light but once it warms up it grts worse and stronger the car also smokes sometime not always. I dont know if it matters but the previouse owner told me he bought the cheaper throttel on the market and it might be from that the codes i get when i plug in the obd sensor it shows 3 codes P0491 , P0121 (shows reacuring) , P0636 (also reacuring)

The thinks i cheacked all the hoses in to the intake and leading from it to the manifold non off the hoses is broken or old (visual checak)
I also changes the spark plugs and coil pack
I cleaned the MAS sensor and inspected the throttle which is electrical (told my brother to press the gass pedal as i tock a look) and its brand new all clean

If anyone had the same problem or could direct me to something i would be very thankfull as im out off ideas


Ps i forgot to add somtimes at randem intervals the EPC light comes on and the car reves itself up and down

Edited by Gino21 on Wednesday 3rd August 20:38

[Scrump]

Those 3 codes don’t seem to be related.
The recurring ones relate to throttle position and power steering system (according to a Google search). So there does still seem to be an issue with the throttle.
Sorry I can’t help more, hopefully someone else will be able to.

[stevieturbo]

Find a competent mechanic.

You've already bought someone else's mess, you tampering with it further and throwing random parts at it is unlikely to help the situation.

Presumably you bought private and not through a dealer ?