I was following my mate the other day in his 300zx N/A and my window was down and I noticed quite a rich petrol smell in his exhaust fumes?? He has de catted it and also has an up rated air filter. Can anybody suggest why this might be?? I was not able to help him. Cheers. Also when he put his foot down I noticed his exhaust smoked.

Could be a few things, I would start off making sure it is firing on all cylinders thru through the rev range, another thing is a duff o2 sensor, dont suppose you noticed what colour smoke was coming out?

Could be a few things, I would start off making sure it is firing on all cylinders thru through the rev range, another thing is a duff o2 sensor, dont suppose you noticed what colour smoke was coming out?

I believe its firing on all cylinders thru the rev range, as for the smoke it was a greyish colour.

If hes decated it it may be over fueling if hes not chipped it. :confused:

If hes decated it it may be over fueling if hes not chipped it. :confused:

Its got a Devin chip.

Grey smoke is common when over fuelling, its not unknown for a coil pack connector to vibrate loose at higher revs due to the plastic lugs on most being broken then settle back down at lower revs so its not so noticable that its dropping a cylinder, worn injectors possibly??? whats the fuel mapping of a Devin chip like??? as usual loads of things may be causing it.

Grey smoke is common when over fuelling, its not unknown for a coil pack connector to vibrate loose at higher revs due to the plastic lugs on most being broken then settle back down at lower revs so its not so noticable that its dropping a cylinder, worn injectors possibly??? whats the fuel mapping of a Devin chip like??? as usual loads of things may be causing it.

Fookin hell mate, you know far to much. LOL :rofl: I will ask my mate these questions tomorrow, thanks for your help guys ;)

This is unlikely for him, but it could be from the timing, from recent experience. Mine was 40 bhp down from being 5 deg out, rich as fook exhaust.