(Sorry for thr repost, I am just trying to get few more data points.)<p>Hello:<p>I have a late model 1.8TQM w/ Neuspeed chip. When I floor the accelerator and have the sunroof open, I can smell my exhaust fumes. They smell rather sulfuric, like a cold Honda. (Previosuly had one) Anyone experienced something similiar with any chip, including Neuspeed? I live in CA, where we have more stringent emissions controls, and before chipping my car was very clean.<p>Sincerely,<p>Tomasz Wojewoda

You probably missed my reply last time (maybe not), but the rotten egg smell comes mostly from a bad/damaged cat converter. Either that, or you are burning a tank of poor quality/brand of gasoline. I would finish the tank you have first, then try a different brand and see if there is any change. <p>Good luck, and lets hope it's not a bad cat converter.<p>Cris <br>

I also have a Neuspeed but no smell...sorry couldn't help more.

Cris,<p>To my knowledge, it doesn't have to be a bad cat. In my previous life I owned a VR6 (with aluminum engine) that would get sulfur smell every time I tanked at Exxon (more sulfur in the gas, I suppose). I was using only 93 gas, so go figure.<p>Apparently there is some chemical reaction between high-sulfur gasolines and certain aluminum engines (someone told me that US gasolines do have more sulfur in them). I also seem to remember that some manufacturers made engine modifications in order to take care of this problem.<p>I am by no means an expert in this, so don't beat me bad if I'm mistaken :)<p>Andrei.

Cris:<p>I got your post. I switched gasoline already, from Chevron to either Shell or Unocal 76. All 92 octane. The cat could be bad, but then shouldn't I smell it all the time, even under part throttle, or when parked? The car ONLY smells under full throttle. I wonder if that is normal for chipped cars. Remember, I live in CA, where cars just don't smell. I visited my parents in Rhode Island, and almost every car smelled to me, even new ones.<br>

Please try this on the way home:<p>Open the sunroof, get into the third or fourth gear, and floor it. Keep it floored for few seconds. Maybe a nice run from 50 to 90 in the third gear! Any extra exhaus fumes?<p>Tomasz

'98 w/Neu, Shell 93 octane, no smell to me (nt)<br>