Thank you for all your comments. The reason for making it catless was to have more exhaust volume at lower speeds not really performance. The tuner who is one of the best in the UK is adamant it's not the tune, the O2 sensor was also turned off if I recall. My bigger worry is with the clunking and metal rattling which I sense may be the gearbox. Will get checked out this weekend.

 

never that bad with 911's due to the engine location, every other car smelled worse (with no cats) than the turbo.

 

Where about's in the UK are you? I can always give you my opinion if you are around london.

 

Put Kline back on with 100cel as the sound isn't that different and no worries for MOT, all good now. Got gearbox checked out, it was fine. Still hear the intermittent clunk, metal sound but car has been examined and given all clear so lets see.

 

The 911 and other cars still exit the exhaust out of the rear doesn't seem to really matter where the engine is located for this problem

 

Never had a problem on my 997tt with 3 different exhausts tried cats no cats etc. email dzenno have him take a look at your tune, second set of eyes. Also if your in e85 it actually smells good. The GtR I just got now that beast stinks like an oil field lol.