I have finished installing my Catback last night and went for a hard pushing test ride. It does makes a good difference in low and medium range Revs but after pushing several times to the limit, it seems that I have lost a bit of top rev power, it stills climb to 7200+ but looks like from 6300 to 7200 the engine is lacking power Is it normal? and if yes, what else can I do to get get this power loss back?

 

After installing and removing my first Milltek cat back I discovered a finger sized piece of exhaust sealant paste straddling the two rear pipes in the collector. I followed the advice of more is better with the paste application.

 

I've read that after about a week of driving the exhaust will break-in and perform better. Whether that is true or not, I don't know. I have about two weeks on my exhaust but still another 400 miles to go before the slow to get there 1250 mile break-in. From the limited speed I'm running, the car does seem a little better than the first week the exhaust was installed. Then again, it could be my imagination.

 

it will get a little better as your exhaust breaks in.. (remember, to wipe your car down everyday.. little steel particles will land on your car from the breakin period)