A daft question about engine management lights and fault codes

SimpleSimon

Well-Known Member
About as off topic as they come, this...

The engine management light on my xtrail came on the other day. I have been driving the car since and noticed no performance issues whatsoever, including a trip to the in laws where the engine would have had a good blast and any flat spots or underperforming would have been noticeable. I bit the bullet today and took it to a local garage for a diagnostic. The verdict was the EGR valve.
Anyway, they've cancelled the fault code and the light has gone out. I know a very competent diesel specialist who works for beer money so the car will be going to him for any work.
My daft question is this: How long does the cancellation last before the light comes back on, and if the light doesn't come back does that suggest some kind of glitch as the initial cause rather than a genuine parts fault?
 
If there's a Fault it'll come back on straight away

if they diagnosed EGR fault can you buy a kit to remove the EGR valves and do away with them altogether ?
 
get rid of the EGR
its there for emissions nothing else
It is also increasing the production of diesel particulate matter, one of if not THE leading cause of lung cancer

if it is goosed the light will come back on when the emissions or fuelling registers as outside the normal range
 
Conveniently I have a long drive tomorrow over a wide range of road conditions, so I'll see if it comes back or not.

Is there a potential MOT issue with emissions if I remove/blank the valve, or is the effect not big enough?
 
What car is it, EGV are notorious on Vauxhalls and had one replaced under warranty on my first Zaffy. Often intemittent problem but can actually expire. I would just keep an eye on it but check you have breakdown cover just in case.

D
 
buy an egr blanking kit and get it blanked off. They put all this cooling of exhaust gasses in with intercoolers etc then return the exhaust gases back to the blinking engine to remove the gnats fart of co2 this does while sacrificing performance and fuel economy!
all youll notice is an improvement in performance, a mile or two better fuel consumption and no warning light...oh, and it should still fly through the MOT.

in edit....I couldnt give a rats ass how much money these car manufacturers spend developing their engines :)
 
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The warning light comes on when a sensors says there's an issue it could be a fault or a faulty sensor or a bad connection. I'd wait and see what happens
 
I got the blanking plate kit for my Saab and it was perfect, the garage fixed the light with a reset and a cancellation of the fault code,

the egr valve was then dumped in the bin, sold the car to a Honda software,engineer in Swindon and he still drives the Saab to this day and says he has never had any issues,

bob.
 
Firstly the car will pass an mot wether the light is on or inop ( trust me I'm a tester) secondly not all cars can have the egr valve blanked off and thirdly, yes it can be just a glitch they tend to block up with carbon build up and sometimes can be cleaned out. Best thing to do is drive it and see if the light comes back on
 
Firstly the car will pass an mot wether the light is on or inop ( trust me I'm a tester) secondly not all cars can have the egr valve blanked off and thirdly, yes it can be just a glitch they tend to block up with carbon build up and sometimes can be cleaned out. Best thing to do is drive it and see if the light comes back on

On slightly older cars those without an ECU removing the ecu was an easy thing to do resulting in less smoke and usually a slightly more responsive engine and sometimes a bit better mpg

Removing or using a blanking plate in some more modern cars can. Be more of a problem as the ECU needs to see the EGR va!he and. A d blanking will often result in the engine management light staying on, its said that drilling a small hole in the plate will overcome this problem in some cases .

Did my Pajero and it made a big difference did 50,000 miles after doing it with no ill effects but it had no ECU, would like to do my present
L200 but a bit more complicated would prefer to remove it completely rather than a blanking plate not sure about the electrical connections
To the sensor,will probably just fit a blanking plate and see how that goes.
 
Apparently you can get the newer cars reprogrammed to blank the egr valves without the light coming on but some eu boffins made it illegal, much the same as knocking the dpf out. You may be able to find someone to do it, although I don't know the procedure or cost .
 
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