I recently installed the 034 MAF hose on my B7 Audi S4 while I was replacing the air filter with a K&N and thought I’d share installation photos/instructions here since I couldn’t find much on the internet. It’s a very simple install and takes about 10 minutes. The only tool you need is a flathead screwdriver, and some pliers (pliers optional). I purchased the hose from JHM here. The manufacturer states that this product is an improvement over OEM based on:
Advantages are: smoother and larger ID for better flow than stock (OEM is necked down to 82mm inside, this silicone hose is 88mm throughout).Made from 4-ply reinforced silicone, features smooth inner bore for maximum flow, good looks and longevity.
You can see in the picture above that it is definitely smoother, and looking down the pipes you can tell the inner diameter is also larger. While I don’t notice any dramatic difference on the “butt dyno”, I think this mod is well worth the $70 if you’re trying to improve airflow into the engine. I had a similar hose on my A4 (034 Turbo Inlet Hose) and also had a good experience with that, which is another reason why I wanted to try out this hose.
Step 1 – remove the engine cover. It pops right off, no tools necessary.
Step 2 – Loosen both hose clamps so that the OEM pipe can be taken off. You will reuse the hose clamps so do not discard them.
Step 3 – Remove the plastic nozzle/sensor from the OEM tube. It will pull out using your hands or a pair of pliers. Be very gentle as you don’t want to break anything, and in my experience the plastic in the engine bay can be very brittle (and expensive to replace!).
Step 4 – Remove the OEM hose and insert the silicone 034 MAF hose with the OEM hose clamps over each end. Insert the plastic nozzle in the factory hole, and then tighten each hose clamp again. Make sure the hose clamps are on the far end of each side of the hose so it is tightening down where the hose overlaps with the respective connecting parts.
Step 5 – Replace the engine cover, test all fittings and enjoy!