Loss of power with exhaust valve mod???

[rikardo]

Hi All

I keep dipping under my car to connect and disconnect those little grren pipes on my exhaust and I'm now certain that i lose power when they're taken off. Yes - it sounds great, but get a marked if intermittent flat spot - occasionally even feels like a misfire at mid-range - and that beatiful 2nd 'kick' at 6000RPM has gone. A real shame 'cus I love the sound. At first I thought I imagined it, but having swopped at couple of times it's definately there. So I now have the choice between sounding great or going fast

Anyone else had the same problem or perhaps have an explanation?

Cheers

[approved]

mines been done and my power doesnt feel down i dont think?

my extra shove at 5000 rpm plus is still there as well...

i know that doesnt help you by way of an explanation but it does confirm something isnt right with yours?

[UNI555]

Have you been plugging the pipes? They must be plugged air tight or you'll lose vacuum.

[pippyrips]

What he said, sounds like you are getting a vacuum leak, even if you have been attempting to block the pipes.

[rikardo]

Thanks guys!

That's what happens when you let someone with little car knowledge loose with a pair of pliers. Guess the Gaffer Tape wasn't enough.....

I'll let you know

[gogsyp]

Just did mine last week.
Put a couple of grub screws into the ends of the black flexi hoses' & tighten the ends up with the end clamps. This will ensure that is no vacuum loss.

[Oli]

Exactly what the fault was with mine - Make sure they are blocked

[baylissboy]

If you don't block them properly you will effect the whole vac system on the engine, ie secondary air system, inlet manifold flaps etc, eventually you will have the engine warning light on.

[Oli]

Doesn't put a man light on or store codes. Mine didn't

[gogsyp]

My EPC light would come on then go out again and eventually the man. light came on. I guess when this happened, it resulted in a total vacuum loss to the whole system.

http://i889.photobucket.com/albums/ac10 ... p/Hose.jpg

[P_G]

Have you got this all fixed now gogsyp or do you still need a cpy of my r/r figures?

[rikardo]

Thanks all!

Problem solved. Plugged the pipes nice and tight and now have great sound and speed to match.

Thanks again for the help

[gogsyp]

I'm all sorted now thanks, just saving up for my X-Pipe & back box from AAS. There is one thing that I have noticed since plugging the rear vacuum pipes, there is now a distinct 'flat spot' at 6000rpm.
I have got no idea why this is but I'm not too concerned because after I get the new exhaust fitted I'm going to get it remapped to iron out any issues.

[silverRS4]

Has anyone had this noticeable power loss without any vacuum problems or MIL light? My car did it briefly a few times several months ago, but now its anemic all the time and has been for quite a while. According to my VAG-COM data-logs (which can actually log torque output of the engine), the torque is down 30-40 N-m and HP is down 40-45 HP. The car is definitely off and its not just fuel or atmospheric conditions. I've tested all the vacuum lines myself and the power flap, manifold flaps, and exhaust (back box) flaps work properly. I'd like to take it to the dealer, but what am I supposed to do without a MIL? Just give them a bunch of graphs and tells them to fix it?