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im still doing research into the milltek system and have come to a crossroads.

is there much of a difference between getting the full system with sports cats vs just getting the cat back system?

could i get custom cats installed after i have tried the milltek catback system?

the pricing of the sports cats has blown me away, i can't believe those things are that expensive.

thanks
will

You can add the cats at a later date after the milltek if you like. It all depends how far you want to take the car. If you are getting the car remapped remember that most tuning companies use a different map when the cats are fitted (so you might have to pay twice for a remap)

Not a lot of point in doing catback only. The real gain is when you change the cats too.

so please explain to me why it is a necessity to get the remap?
does the cat alter the flow by a huge amount?
there always seems to be 2 sides to the argument and i can never get a real answer to this.
some people say the oettinger chip will adjust itself while other chips dont but then some people say that all chips need to be remapped.
im confused.

It's all about windows. The ECU can adjust a certain amount on its own but if you've increased the air thoughput then possibly the fueling is at the higher end of the window. If you have a chip then the settings allows more adjustment around the centre position. This give the possibility of, for example, further retarding the ignition and hence getting more power.

At least that's how I understand it.

Scotty wrote:It's all about windows. The ECU can adjust a certain amount on its own but if you've increased the air thoughput then possibly the fueling is at the higher end of the window. If you have a chip then the settings allows more adjustment around the centre position. This give the possibility of, for example, further retarding the ignition and hence getting more power.

At least that's how I understand it.

I could be wrong here, but i believe at WOT it works off a fixed map, and doesnt self tune as such. <seeking experts advice please !>

I don't know the exact details but I have had direct experience. My car benefitted significantly from a remap (increased fuelling at the top end) after the Miltek DPs and cats were fitted.

Don't forget that, as Scotty stated, the ECU only makes relatively minor adjustments within the 'framework' provided by the mapping. The cats do indeed increase gas flow significantly at the top end, so perhaps this 'framework' needs adjusting.

We have been having a similar discussion in another thread concerning the AmD mapping.

I suggest you contact some local tuners and ask them. That counts more to you than the opinions of enthusiasts in different countries.