Rough Idle

[eggy524]

Hey,

I've posted here before about my car and its rough idle. Originally I thought that the issue was down to the EGR valve being clogged up with dirt but it looks like this isnt the case anymore!

The car has been idling rough for about a year now. The rev counter just sort of dips every 1-2 seconds when the car is idle, sometimes making it stall.

I hooked up the computer to the car and it gave a few faults:

16785 - EGR System: Insufficient Flow
17851 - EGR Valve Position Sensor Signal too low
17808 - EGR Valve Circ Electrical Malfunction

Looks like an EGR problem to me! So I went to a local garage and asked them to take a look at it. (They specialise in volkswagen cars so know what they're doing)
The problem is that they couldn't find the EGR valve in the engine bay at all! They knew where it should be but in its place was just a blanking plate and a connector where it should have been plugged into! There is also no hole drilled into the exhaust for it to connect into so I know it hasn't been taken out!
So, no EGR valve was installed from manufacture!

Does anyone know why the car is bringing up those engine fault codes if it doesn't have an EGR valve.
Secondly, how would I fix the rough idling? Got the throttle body cleaned a while ago but that hasn't solved the problem!

Thanks

 

[phey708]

Did it show any faults in relation to fuel?

It will still show errors about the EGR valve dispite the absence in your case. 17851,
17808 will occur if the plug is missing from the EGR or the wire to the EGR is corroded and is misreading.

 

[eggy524]

No, nothing in relation to fuel.

There were two others but they were to do with the air conditioning unit

 

[krussel]

I am no expert but it sounds like your car has been modded

I always thought that you simply slipped the EGR blank plate in between with a hole drilled or not and left the EGR still attached ?