I have had a Magnex downpipe just fitted and unfortuantely bought it a while back from Power Engineering. The exhaust has been fitted but the Lambda sensor just wont seal to the exhaust. So the idiots at the garage managed to weld the lambda sensor to the fixing nut. It doesnt stop the oxygen leaking but stops the annoying rattle. cost me about £150.00 fitting. So I phoned Power Engineering and they with Magnex have just replaced my Downpipe with apparently a redesigned version. Now reading this article I am starting to worry incase I have more problems with the pipe I have just been supplied. Because I am now gonna have to buy a new lambda sensor and have the whole lot refitted. Which is gonna cost another £150.00 and then the £115.00 for the lambda sensor. I think its great that Magnex and Power Engineering have replaced the Downpipe so quickly but also really dissapointed that the two companies have sold the down pipes originally without checking the fitments and therefore costing Impreza owners more money for fitting. Anyone else suffering with same problems I would like to hear from you. Also would like to have a response from magnex as to the situation you seem to have created for Subaru impreza owners.

 

Sorry to hear that, I have got a Magnex redesigned downpipe on my WRX. Won't they give you a replacement one? Swap with maybe a bit of cash?

 

There was a post on here, yesterday, from Magnex. They are asking for a donor car so they can sort the fitment issues out.

 

Power Engineering have replaced the Pipe but wont say upfront if they will pay for fitment. Magnex angle seems to be you have bought it from Power Engineering so deal with them and the other issue is. If they are asking for donor cars to trial fitment will this pipe be any better or will i be left with another pipe and another £150.00 exhaust front pipe fit.
The other interesting point would be what if the lambda sensor richened the fuel to a point it caused damage to the engine whilst running because it wasnt sealing to the exhaust. Would Magnex or Power Engineering accept responsibility.

 

Question, this Magnex downpipe, does it replace the cat down pipe?

If it does I noticed the same thing on the Magnex downpipe I brought, the sensor just does not screw in enough and so rattles. Originally I used a small Jubilee Clip to take up the slack. BUT then I had a think about it and realised it is there to measure after the cat to measure that the cat's up to temperature (not Lamda), as there is no more cat I tried the vehicle with the sensor unpluged totally (the connector is just behind the air filter box) and found that its not needed. The sensor is closed circuit when the cat and exhaust is below temperature, so as no cat it will change resistance Very quickly and go open circuit and be useless. So the boss was welded over and the car was run like that with no probs. And the car is still running fine with the new owner.

 

Thanks Tizard So where is the Lambda sensor then mate as on my car there was originally two cats a large one behind the sensor and a smaller one in front of it. I was told by a Subaru Dealer it was a Lambda sensor and Magnex when they have supplied the new pipe that part of the pipe is slightly modified a bit longer to seat the Sensor into.

If this is a temperature sensor to monitor cat temp does this mean the engine management trys to get the cat to warm up fast by increasing fuel. I really dont know. Just don`t wanna blow the dam thing up.

Anybody else with other ideas all suggestions welcome and appreciated