I have a 2002 A3 1.8T AUM and I noticed something a couple of days ago: after normal driving(cruising at 100km/h in 5th gear on relatively flat roads), the exhaust manifold was glowing red, but it was not a strong glow - maybe during the day would have been unnoticeable. Today, after a similar drive I stopped and checked again and there was a similar light glow. Afterwards I was curious if I push the engine a bit, how much stronger the glow will get. So I drove in 4th gear at around 130-140km/h on a 1.5-2km stretch of an uphill and straight road. When I reached the top, all the exhaust manifold had a very strong red-orange glow.
Is this glow normal on 1.8T engines? Engine has no error codes and it seems to work like it always did(pulls strong and normal fuel consumption). For the past year, I'm running an AUQ ECU but everything else is stock. Also, in the last couple of months I used only 98-99RON fuel. Could the ECU or the higher octane fuel cause the exhaust to glow? Or there is another problem? Would a clogged exhaust catalyst have some noticeable symptoms?
Is this glow normal on 1.8T engines? Engine has no error codes and it seems to work like it always did(pulls strong and normal fuel consumption). For the past year, I'm running an AUQ ECU but everything else is stock. Also, in the last couple of months I used only 98-99RON fuel. Could the ECU or the higher octane fuel cause the exhaust to glow? Or there is another problem? Would a clogged exhaust catalyst have some noticeable symptoms?
