m.serra99

Hello, I wanted to ask for help for some problems I have with my 06/99 S4 b5 Avant.When I press the accelerator to the floor, it seems to go well, until 3,000 rpm when I notice a small loss of power, but at the same time, perfectly maintaining the turbo pressure, and as the revolutions increase, around 4,000 rpm the light begins to flash. of the ESP (yellow triangle), in the frame, sometimes causing jerks.I don't use Vagcom very well, but enough to make some logs in 4th speed.All cylinders delay ignition, up to -9kw at higher revolutions.Bank 2 (4,5,6) a little more than bank 1.I have tfsi coils, ramair intake, new bkr8 spark plugs, nulled icm, completely decatalyzed downpipes, 034 intake manifold gaskets, reinforced hoses, larger intercoolers and some other modifications.but I can't find the problem, Vagcom doesn't register any errors... so I'm lost and I'm asking for your help.thanks a lot.

AudiAllTheWay

Is it possible there is an intake air leak? Check the Bypass Valves as stock rubber diaphragms tear with age and aftermarket valves can use a periodic clean and lube. Hopefully you’re not using blow off valves. Can make a pressure tested from hardware store bits and clamp onto the air filter end of the Y pipe. The large one is for 2.7T’s and the small one is for 1.8T’s. For 2.7T disconnect the PCV connection at Y pipe and plug the Y pipe hole with your thumb while applying pressure. Caution to not over pressurize the intake as 5 - 10PSI max is needed to find air leaks. It is normal to hear air bubbles in the crank case oil when doing the test. Also could be a flakey N75 valve. Check your PCV too as they don’t last forever.

AudiAllTheWay

If ESP light is turning on then post the Vag Scan results from Address 01: Engine and Address 03: ABS Brakes

MarkDoronin

Mate, what did you get as a result?