Underneath the throttle body on my 2002 Fabia 1.4 16v there is a chamber with what I would desribe as an almost fallic symbol sticking up with vents at it's top end. Could somebody explaint to me what's the function of this and should it be cleaned. It looks like there's a bit of gunk inside it looking at the top vents. What's to be found at it's base? Thanks and sorry if this is so basice.

No replies. The reason for my asking was that I've got an EGR fault reading. I've cleaned the throttle body but I've still got the engine management light on. Not sure what to do now.

I believe that what you are referring to is the MAP sensor. I might be wrong though. This doesn't have anything to do with the EGR. I believe that it isn't uncommon for the EGR to need to be replaced; apparently cleaning doesn't often work. Also, it sounds like you have only cleaned the throttle body; this is not the EGR valve.

Hope that helps

I'd guess a throttle body heater, but I don't know for sure.

It's the end of the egr pipe. If you have a low flow fault then the egr valve/pipe could be blocked, if you have a high flow it could be an air leak on one of the joints. Do a search, there's loads on this.

It's the end of the egr pipe. If you have a low flow fault then the egr valve/pipe could be blocked

Oh right, so I was only completely wrong then :twirl:

It's the end of the egr pipe. If you have a low flow fault then the egr valve/pipe could be blocked, if you have a high flow it could be an air leak on one of the joints. Do a search, there's loads on this.

I have hight flow....according to the fault test result. The last couple of days....the Engine Management fault light went out.....but this evening, it came back on again. How would somebody interpret this? Does it probably mean that the problem isn't that serious or what? Does the fact that the light went out mean that the EGR itself is probably working? Any suggestions?

On top of the EGR valve there is a variable resistor that moves as the EGR valve moves, it is the value of this resistance that the ECU uses to determine the position of the valve. As the EGR valve is opened the ECU expects to see a change in the exhaust gasses. My theory is that if the ECU doesn't see the expected change in the exhaust gasses, it will open the EGR valve some more. If the pipe is blocked the ECU will have the EGR valve fully open without the expected change in the exhaust gasses and will throw an excessive flow code even though the gasses aren't getting through.

What we usually try is a clean of the EGR pipe and throttle body, followed by putting the throttle body into basic settings and 'exercising' the EGR vlave through the VCDS output test setting. If this doesn't work, the we replace the EGR valve.

My high flow was due to poor joints either side of the egr valve body, letting air in to the inlet manifold. They are metal so they tend to get re used, but the new ones have a black coating which provides an effective seal.

Thank you both for your replies. I detached the egr pipe from the egr valve a few weeks ago. It was a real struggle as it's a metal pipe and there's very little give. I was worried I wouldn't be able to get it back on but I did somebhow manage to prize it back on eventuallu. I'm sure I would have to undo the screws on the throttle body end too. It seemed like a big job to be because it looks like it will be difficult to get at it. Do you think I'll be able to do this myself or would I need to get the garage to do it? Thanks.

If you remove the nuts and studs from the valve body where the pipe joins to it, you can just slide out the valve without disturbing the pipe. If you have already disturbed the pipe, it may be that you need to replace the joint (gasket) where it connects to the throttle body or maybe check it's tight. There is another joint halfway along the pipe which is a pig to get at, but hopefully you won't have disturbed it. New joints are a dealer item but don't cost much.