Air leak

[mty12345]

This is my problem, is a faulty sensor the obvious fault that would cause these symptoms? Or would an air leak cause a working sensor to throw up fault codes? For all i know, the sensor is just doing it's job. £130 is a lot of money for a part that i may not need, so i hope you can see where I'm coming from.

Hi mate, that first code P0402 is for the EGR http://wiki.ross-tech.com/wiki/index.php/16786/P0402/001026

If that has failed or stuck open, then that will mess the mixture up, although your codes appear to be for the heating part of the lambda sensor/circuit http://wiki.ross-tech.com/wiki/index.php/16414/P0030/000048

I'd be checking what the EGR fault is, and also checking for damage or corrosion to the electrical connections to the lambda, before i splashed out on a new sensor.


Edit if you can get the proper 5 digit Vag fault codes, that will probably show a lot more than just the generic OBD2 P0030 codes

 

[Ibizatime]

@RUM4MO It has had a whole new exhaust system fitted, so no leak there. It just sounds a bit like an exhaust leak. The engine sounds rough while accelerating.

@mty12345 I think the EGR fault is down to a bad connection, I will have a look tomorrow. I will also get the the vag codes while I'm at it.

Thanks

 

[RUM4MO]

The EGR valve on these petrol engines does not normally cause problems, ie it will not get choked up in its own body, but can get choked where the aniconic piping connects to the TB, or at least at the port on the TB or its adaptor plate. Normally that will get logged as minimum flow, but I think that once, with a choked EGR valve pipe, I got excessive flow logged.

Maybe there is a leak at one of the joints at that EGR valve, at the exhaust area end, there is an adaptor that will have two gaskets and another gasket at the TB end of that metal pipe.

Maybe use a mirror to check that the closure seal (part of the EVR valve assembly at valve factory) has not started leaking or got blown out, that has been reported a couple of times in these forums.

Edit:- just in case that you are tempted to remove that EVR valve assembly, you should buy the three gaskets first, two of one and one of the other, also that metal pipe has a support clamp roughly at the highest point of the bellhousing, maybe it uses a small screw fixed into the thermostat housing block.