[wainfleetnick]

every now and then my astra starts to chugg and then when i come to a junction and ride the clutch it will cut out . this happens more frequently when i go up and down hills.year 2003 , 1.6 sxi petrol. thanks nick

[Hometune]

Is your engine 8 or 16 valves?
If its an 8 valve, check the small rubber pipe from the rocker cover to just after the throttle body. They are too long and when hot collapse. This causes stalling/cutting out etc. Easy fix - just trim about half an inch off the one end and refit.
If it is the 16 valve engine, check the engine breather pipes for sludge and gunk which collects in them.

[ivor.T.]

pretty common for the E.G.R valves too become clogged with carbon deposits and cause them too stick open which would give the faults described their is a few options remove and clean the valve then put some fuel treatment through too prevent further build up. or a new valve fitted also some fuel treament too prolong life of valve forte is the brand i normally recommend or if you go too vauxhall they will remove valve fit a blanking plate and re map the ecu too run without the egr valve operating personally i dont like the last repair as the engine was designed too have an egr valve

let me know how you get on

[Hometune]

This is not quite accurate. The EGR valves do not become clogged with carbon, that happens with sooty diesels ;)
The problem is in the shaft tolerance inside the valve itself. Over time it wears or becomes corroded and eventually sticks. This causes the voltage required to move the motor to increase and this is shown on scanners as the feedback voltage. Sometimes scanners show this as code P0400 - EGR valve flow insufficient. Blocked breathers also show this code so beware.
There is a simple fix where the top of the valve is drilled with a 3mm drill so you can knock out the shaft. Then you can clean it all up reassemble, seal the drill hole and it costs nothing :D

From 2004, Vauxhall fitted blanking plates where the EGR would normally sit and remapped the ECU as a matter of course. Unless you have Vaux-Com or Tech 2 this modification is not recognised by other scanners and code P0400 still comes up.