These Three Easy Fixes Transformed My 2002 Audi S4. What Easy Fixes Made The Most Difference To Your Car?

It’s not all too often in DIY wrenching that something requiring very little effort makes a big impact, which is why I’m so thrilled with the transformation of my beloved 2002 Audi S4.

I picked up my example of this iconic late-’90s/early-’00s German sports sedan at the end of 2022. Just $925 plus fees from Copart put my name on its pink slip. Previously, I wrote about some of its lovable/hate-able foibles at The Drive; long story short, there have been plenty of signs indicating deferred maintenance before it got to my driveway. Plus, the fact that its twin-turbo V6 is crammed between its narrow, compact car frame rails makes any degree of wrenching a bit more complex than other cars. It’s been a heck of journey nursing it back to health—or keeping it barely alive, depends on how you look at it.

Which is why I was over the moon when these three recent, simple fixes paid off so well. Here’s how spacing out its wheels, installing an aftermarket front sway bar, and fixing a boost leak made my S4 look, handle, and perform better than ever.

How It Should’ve Come From the Factory, In My Opinion

Alright, maybe this doesn’t necessarily classify as a fix, but it sure did make a big aesthetic impact: Installing 10mm H&R wheel spacers.

Cars often show up on the dealer floor with wheels deep in their arches. But it doesn’t look as good, and I didn’t realize how much of a visual difference it’d make until I did it.

Throwing on wheel spacers is a very easy modification to perform. In fact, I like to think of it more as a mild alteration than a modification. Step one: Acquire spacers from a reputable brand. H&R’s are legal in the eyes of Germany’s ultra-strict vehicle parts legislation—known as TÜV—so they’re good enough for me. Step two: Acquire longer wheel bolts. Step three: Safely jack up and support the car and install at each corner, and it’s a good idea to very lightly coat each spacer with anti-seize along the way. Done!

Even at stock ride height, my very factory  S4 looks so much better. Its OEM 17-inch Avus wheels are more prominently displayed and line up better with its sleek sedan shape. Though, there are also downsides to keep in mind, such as the tires throwing more dirt and debris onto the fenders, doors, and rear bumper. Then, moving each tire closer to the inside of its respective fender could result in rubbing and potentially tire damage, so it’s important to make sure there’s ample range of motion. My car isn’t lowered and I haven’t experienced any rubbing across all degrees of suspension movement since installing them, so I’m in the clear.

[Ed Note: Here’s suspension-engineer Huibert Mees’ take on wheel spacers (it applies to lower-offset wheels, as well). There are some significant drawbacks worth noting. -DT]

Cleaning Up Its Handling In the Twisties

Next up, I installed an H&R front sway bar on my very front-heavy little Audi. And boy, do I mean heavy; to accommodate the massive Quattro all-wheel drive system, the S4’s entire engine sits ahead of the shock towers. This doesn’t bode well for overall handling—usually, the farther an engine sits behind the shock towers, the better.

Installation was almost as easy as installing the wheel spacers: Safely jack up and support the front end with jack stands, unbolt the old bar and brackets, install new bar and brackets … done!

Sway bars help reign in body roll under cornering, and this did exactly that. A more substantial improvement in this department often comes from installing a rear sway bar on this chassis, but this made a very nice difference, too. On stock springs before the bigger bar, the front end felt vague and downright sloppy on twisty roads. Now, it feels a lot more taut and confident, and steering weight loads up a tad more in corners. I haven’t noticed an increase in understeer, either. As far as downsides go, well, I have yet to find any. Bumps are more pronounced through the steering wheel, but not to any annoying degree.

Chasing Boost Leaks

Ask any B5 S4 owner, any real B5 S4 owner: It doesn’t matter if your car has 50,000 or 200,000 miles, boost leaks are boost leaks.

After fixing some light boost leaks over a year ago, throwing in fresh spark plugs and coil packs, remedying boost solenoid-related codes, and installing a new mass airflow sensor, I started to feel a general loss of power, plus some stumbling under wide-open throttle. One day while out running errands, the potential cause revealed itself quite prominently: the unmistakable sound of compressed air escaping from boost piping while driving alongside parked cars.

I’ve had to reinstall and tighten the connection between the right-bank turbo and right-bank intercooler before, but that wasn’t the issue this time. After popping the hood, thankfully, the issue was easy to find: The OEM throttle body boot finally tore. It happens to every B5, I’m surprised that it took this long for mine to die.

As luck would have it, a beautiful Imola Yellow B5 S4 was sitting in a local junkyard 30-or-so miles from me down in Orange County, so I headed out to see if I could pull anything useful off of it. The luck continued: I grabbed its sturdier-than-stock aftermarket Samco throttle body boot, plus better-condition bi-pipes—those are the two pipes connecting the intercoolers to the throttle body. Plus, all the clamps holding it all together, as they seemed to be in better shape than mine.

Upon returning home, I swapped it all in and went for a test drive. The mighty twin-turbo 2.7-liter V6 not only ceased stumbling with my foot to the floor, it felt stronger than ever. In fact, stronger than I thought it would. I’m wondering if my old clamps were possibly a little weak and letting a teeny amount of boost pressure out, though I had previously tested it for leaks and everything looked good. Regardless, I was over the moon.

Despite having a turbo on each cylinder bank, the US-spec B5 S4 only makes around 250 horsepower and 258 pound-feet of torque from the factory. That’s not nothing, especially for its era, but these things are a bit heavy at 3,600 pounds. Mine’s also a five-speed automatic, so it’s not the quickest-shifting box out there. Yet, I clicked off a 0-60 mph run in just over five seconds while merging onto the highway, which seems awfully healthy for an auto with deferred maintenance and 135,000 miles on the clock.

Maybe it’s a testament to my attentive restoration, but I think it may have more to do with its tuning; there might be a tune on its ECU that ups the boost pressure a tad. One way to find out is installing a boost gauge, which I plan to do very soon.

But Can I Rest on My Laurels?

The days following all of this were such a treat: My dear rescue Audi was not only more powerful than ever during my ownership, but also looking and handling great to boot. While I’ve spent a lot of time, money, and effort on the ol’ steed—more than simply buying one used from a fellow enthusiast like a normal person—I’m proud to have put it back on the road. Thing’s helped me become a more confident and capable wrench.

However, a new issue cropped up about two weeks later: Its light tick upon startup turned into a constant tick. Boy, the fun never stops with this thing. Listening closely with the hood open, I could tell it was driver-side valvetrain related, and not the injectors or a cashed rod bearing. I attempted to remedy it with an engine flush, followed by fresh oil and a Liqui Moly hydraulic lifter additive, but to no avail. Pulling the valve cover instantly revealed the issue: Several caved-in lifters, though every camshaft lobe thankfully looked to be in good shape. I guess that’s what happens when deferred maintenance meets frequent peak boost.

I’ve ordered new lifters and other miscellaneous parts, and just have to find the time to accomplish this lengthy job. It’s a great learning experience, I’ll just keep telling myself.

What are some quick fixes that transformed your car, and that you perhaps wish you’d done sooner?