dvfosho6

Hey guys, I just bought a 2003 Audi A4 3.0 quattro and it has a few different issues that I need help with.

First the brakes are hard to press down. I read that this is either a vacuum hose or servo/master cylinder. Hoping it's just the hose but not sure where that's located.

Next I have the P0171 system too lean, I'm guessing this one is easy as I checked a vacuum hose and it does have a crack in it(I thought the hose was the brake booster hose that was causing the brakes to fail) its has a check valve in it.

Last is all cylinders but number 3 are miss firing.

Please help this broken car and overwhelmed man!

lyleswk

Would start by fixing any vacuum leaks. They can sometimes cause the misfires.

dvfosho6

So I replaced the vacuum hose, and another one that I broke while fixing the other and nothing! I scanned it again and got two more codes now. C02E5 Chassis and P0741 Power train Torque Converter Clutch Circuit Performance or Stuck Off.

I'm lost at this point.

lyleswk

You are just going to keep at it. With a car that you know nothing of the history on, it will take time to sort issues out.

dvfosho6

This week I'm going to bleed the brakes, replaced all vacuum lines because I found a couple more that are cracked, replace the PCV, and valve body gaskets..I'll update once its all done.

turbo510

All of those complaints could be caused by an air leak. When running, listen for a hissing sound, particularly around the brake booster hoses, which it should not have if everything is right. Also, be careful while bleeding the brakes to not let the reservoir level get low enough to draw in air, or you'll have trouble getting it out of the ABS unit.