I have a berk 63mm test pipe on its way to me as my cat started rattling. I have a totally standard MY04 and was planning on doing the UK exhaust mod to.

Having done some research on decatting I have read that you shouldn't run a test pipe without tuning due to running lean! Is the test pipe going to effect my air/fuel ratio that much on an otherwise standard car.

I'm worried that running lean could do some damage.... Only reason I went down the test pipe route was purely for noise and not looking for gains but don't want to be losing any ponies due to the test pipe either........

 

test pipe will make a car run leaner. I don't think it will to the point to be worried though. Many many people due run them without tuning on an S2000. You will get better gains for sure with tuning though since you can lower vtec engagement quite a bit once you install a test pipe.

 

Thanks for the info, as long as running a test pipe won't cause damage I'll go ahead and fit it. Not really looking for more power but say I had the Greddy eManage Ultimate (I see is in the for sale section!!) would that be a good option for mapping?

 

If you can find someone to tune it. Not many places tune the Greddy Emanage ultimate unfortunately.

 

Is there a different between a Decat and test pipe? Aren't they essentially the same?

 

Decat and test pipe ^^
the same

 

The S2000 runs extremely rich and the test pipe will make next to no difference anyway. It'll be fine.

 

That's what I like to hear!

 

On a related topic my S with a decat and spoon N1 with spoon intake. I'm currently running a Spoon ECU and it does smell a lot of fuel and when I changed the oil it smelt of fuel. Anything to worry about?

 

Great to hear, I'm running a stock car (K&N in OEM airbox) with the 28mm exhaust mod and will be fitting a de-cat on Saturday to try and release a little more noise... I'm happy to hear I won't need a dyno tune to keep it safe