Cat delete & O2 sensors?

[notech]

Originally Posted by Timco

The feedback from those sensors is not just FYI to the engine, it does change operating conditions.

I don't want to be mean, just curious,
with test pipes I feel sportier sound, car revs faster and generally feels quicker.
What changing conditions are altered without secondary O2 sensors in? Sure it doesn't feel worse than stock.

[notech]

Sorry guys, I didn't give a lot of attention till yesterday,
I saw my secondary CATs come with an 02 sensor at the begin of the CAT and then an 02 sensor at the end.
Is this normal for a 2003 year car? I thought these MY03 have one 02 sensor on primary CAT and one on secondary CAT.

[Timco]

The Fab Speed pipes I bought has a front and rear bung for your O2 sensors. I had to plug both on my pipes since only the forward cats have sensors.

[edc]

I don't know what your emissions test is like in Gibralter but no cats in UK would surely fail. As you have found out Euro cars only have 2 cats, what everybody else here calls secondary cats. I have just fitted 100 cell sports cats and had to space out the rear lambdas in an attempt to stop the CEL triggering. I guess you will need something similar.