Can egr cause misfire?

Juicy

Active Member
Sep 20, 2014
64
0
As above really, it's constant misfire now and is giving me a headache,
 

Scotsmin71

Active Member
Apr 16, 2015
25
0
Nairn, Highlands
My personal experience with the EGR valve is that it doesn't misfire during normal driving. It is recurring at idle however. I would check your spark plugs and HT leads also check the connection at your dis module to see if they have popped off.
 

Juicy

Active Member
Sep 20, 2014
64
0
It's had new coil packs and plugs, was fine till I unplugged egr valve then after 10 mile it started missing.

Cleared after I cleared code but not 2nd time
 

Scotsmin71

Active Member
Apr 16, 2015
25
0
Nairn, Highlands
Is your car misfiring whilst driving and at idle? I would run a full diagnostics before going any further. Just out of interest what make model etc do you have? I have a 1.4 16 valve Ibiza se sport 02 plate.
 

Juicy

Active Member
Sep 20, 2014
64
0
Yes on idle and driving but first time it did clear for few mile when I cleared egr code.
its 1.2 ibiza 2002
 

Scotsmin71

Active Member
Apr 16, 2015
25
0
Nairn, Highlands
Check the throttle body and clean with carbon cleaner would be my next guess. There are a good few you tube videos as a guide on how to do this. Seems the only other common cause of both idle and driving misfire. Have you got a diagnostics set?
 

Juicy

Active Member
Sep 20, 2014
64
0
I think I've cleaned it while back. Got ethos diognostic equipment,
 

Juicy

Active Member
Sep 20, 2014
64
0
Tried to post picture but 3 codes

17851 (p1433)

16585 (p0201)

16685 (p0301)

But egr is unplugged whilst scanned
 

Scotsmin71

Active Member
Apr 16, 2015
25
0
Nairn, Highlands
OK your misfire is on Cylinder1 p0301 there is a injector circuit fault in electrical circuit on cylinder 1 p0201 and secondary air injector system pump relay circuit is open. I would check the connection to your injectors this is where the issue is. From memory cylinder 1 is the one nearest the drivers side. The connection will be loose causing the misfire.
 

Juicy

Active Member
Sep 20, 2014
64
0
if my coil pack on number 1 is faulty could this also be it? Or plug even?
 
Last edited:

Scotsmin71

Active Member
Apr 16, 2015
25
0
Nairn, Highlands
No your injectors are at the rear of the engine. They are a plastic rail with 4 electrical connection. It is either been pulled out or broken by accident when fitting your spark plugs and leads. Check that the connection on the injector rail is fitted. Try that first
 

Juicy

Active Member
Sep 20, 2014
64
0
No I know what injectors are, I'm a mechanic but I glanced at injector and it looked in and ok as I pushed top of it to check but only quick, so it may be ok.

What makes you say it's the injector?
If it's missfireing it could be spark, fuel or compression right?
So if compression is there cos it cleared with codes last time, fuel maybe there as it smells strong of fuel when missing, it could be faulty plug or coil pack that I bought?

What about those codes tells you injector?

Thanks alot for your help
 

Scotsmin71

Active Member
Apr 16, 2015
25
0
Nairn, Highlands
The codes you gave me are faults for cylinder 1. Code P0201 is Cylinder 1 Injector circuit fault in Electrical circuit. Code P0301 is Cylinder 1 misfire detected. So both of these would indicate to me that the misfire would be caused by an electrical fault in the injector circuit. Hope this helps? The final code P1433 is secondary air injection system pump relay circuit open. I would guess that the injector is not operating because it is not receiving power. It will still receive fuel hence the smell but won't be able to inject the fuel because there is no power going to it. The misfire is most definitely on cylinder 1.
 

Juicy

Active Member
Sep 20, 2014
64
0
Ok thank you for explaining mate, so the codes state injector fault in the codes?

So my number injector may be buggered if 1st time it cleared with code?
 

Scotsmin71

Active Member
Apr 16, 2015
25
0
Nairn, Highlands
There is an electrical fault in injector No1 most definitely. If it cleared the fault the first time but not the second time I would retrace your steps. If no injector was touched I would think there is a fault with any connections.
 

Juicy

Active Member
Sep 20, 2014
64
0
Ok thank you for your time I will take a look tonight over it and let you know. Could it be an earth?
 

Scotsmin71

Active Member
Apr 16, 2015
25
0
Nairn, Highlands
It could be they are known to have weak or poorly positioned earthing. Having had a VW Polo before I am shocked at how little wiring they use. With VW there was a degree of play with Seat it is to the mm. Can easily see wire's being pulled.
 

Juicy

Active Member
Sep 20, 2014
64
0
Well there's earth on top of rocker cover, cleaned that and cleaned gearbox side of earth from box to body
 
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