<center><img src="http://pictureposter.audiworld.com/110172/rs-4_with_horses_crop_.jpg"></center><p>The EPC light came on late last week. A quick review of the manual (it wasn't the gas cap) and some restarts and it went out but the CEL stayed on. The dealer found a pinched hose under the intake manifold...WTF. It is OK now but had a 27 mile 'test drive'; ostensibly to check the EPC on cold restart. Has anyone else had a pinched hose problem...on an RS-4 I mean.

They checked and fixed this for my EPC light the first time. Second time they replaced the intake manifold due to stuck flaps.<ul><li><a href="http://www.jlosee.com/images/RS4/PDF/TSB-RS4%20Manifold-2.pdf">http://www.jlosee.com/images/RS4/PDF/TSB-RS4%20Manifold-2.pdf</a</li></ul>

...last 2 weeks and it sort of ticks me off. I thought it might be the gas cap (since it went off both times about 5 starts after I tightened the cap), but 2 times in a 2 weeks just seems odd. I've got to take the car in for a mid-interval oil change and DRC check (yes, I'm getting clunking in the front drivers and rear passenger side) so I can't wait to see what they find when then run the VAG tool.

Mine has been in for this EPC issue and had the intake manifold and vacuum lines replaced. The problem was fixed. Just yesterday though I'm noticing that the power bump at around 5,000rpm isn't coming on any more. I tried in several gears and confirmed.

But no EPC or CEL!

What you're describing happened to me twice. Can you log timing retardation in a few cylinders along with engine load? All the variables that contribute to the "bump" in power are directly related to engine load. What seems to happen is that timing is retarded by the ECU(for whatever reason) the load% falters along with it and the "bump" never occurs. I wasn't able to pinpoint anything exactly because in both cases, the problem went away after I finished the gas in the tank and put 100 miles or so on a fresh tank of gas. The odd thing was, both cases occured after my wife filled the car with gas. She insists she puts in the 91/92...who knows. Since there's no CEL, hopefully its only temporary in your case as well and could be a simple fuel issue.

About the relation to load. I noticed this morning on the way to work that the power bump was there and came on strong. The engine was still cold (ie, the 7,000rpm rev limit had disappeared and the engine oil temp was over 90C)

I also notice that the power bump doesn't come on when the engine is hotter, say over 105C.

I only use 94 Octane gas here in Canada, but perhaps it was a bad batch. I will fill up again later today and see if it goes away or not. Otherwise, I need to find someone with a vagcom that I can borrow for this info.

- Amir

Do you have connections in MT?