Exhaust      
Cat: Symptoms of bad cats?
DP: Any gaskets needed between dp's and cats?
DP: APR old DPs vs new DPs (Mark P)
DP: Autospeed testpipe pics
DP: Considering DP's?
DP: DIY Down Pipe gutting
DP: Downpipe head shields, are you running them Yes or No Please
DP: Downpipes comparison
DP: Gutting Pre-Cats by CJ-S4
DP: Gutting the Pre-Cats by lemieux
DP: In the middle of Labree install....questions.
DP: Labree (New) downpipes have a spacer that will fit K03 and K04 turbos
DP: Labree install.... heatshild & O2 sensors
DP: Pics of the ASP DPs and True Dual cat back with 200 cell cats
DP: What do I need tp attach the ASP pipes to the stock DPs? They're the same size, won't fit into
DP: What is the difference between Piggie and LaBree DPs?
EGT: (Exhaust Gas Temperature) Sensor Installation/Information
EGT: Sensor Replacement 
EGT: What symptoms were you having?
Exhaust:  clamp question
Exhaust: Anyone one use dynomat or equivalent to reduce exhaust volume/drone?
Exhaust: APR Exhaust new vs. old (Mark P)
Exhaust: APR: Is this the determining feature between APR exhaust v.1 and v.2?
Exhaust: ASP: ASP Exhaust just arrived. Are there any installation issues that would prevent me from getting ...
Exhaust: Audi Collection Exhaust, first impressions
Exhaust: Auto Speed Performance Tru-Dual225 Exhaust
Exhaust: AWE Twin 1 and Twin 2 install
Exhaust: AWE Twin2 Review and comparo with my autospeed dual
Exhaust: Is there any proof/opinions on a true dual system giving better performance than a 3" system?
Exhaust: What exhaust clamps should I get ? Torctite?
Manifold: Are exhaust manifolds worth it when going stage 3?
O2:  Plug anti-fouler - You would think that the non-fouler O2 mod would be pretty easy, but
O2: 1000 mile non-fouler 02 sensor mod update.
O2: 2 questions for tweaking/logging braintrust....WOT 02 - CF - KV
O2: A.) Does the ECU take the average of the 2 values or what? B.) How much is that affecting power output? 
O2: Anyone else think the discrepancy between my bank 1 and 2 O2 sensors looks fishy?
O2: anyone know where i can find more info on O2 simulators?
O2: Anyway to clean O2 sensors?
O2: Are my 02s backwards?
O2: graph of O2 voltages at different primary fuel trim levels: (open for interpretation)
O2: I'm interested in purchasing a wideband 02 sensor setup
O2: Install the secondary O2s backwards?
O2: Is there a write up, with pictures, for replacing O2 sensors?
O2: Looks like there's another Wideband O2 option out there...
O2: O2 non-fouler mod does NOT work with Zoldman O2 sensors.
O2: People who have or had Labrees (16805/16815)
O2: Plug anti-fouler - More on spark plug anti-fouler O2 mod.
O2: Plug anti-fouler - Spark plug non-fouler
O2: Plug anti-fouler O2 sensor mod seems to be working so far.
O2: Poll: those of you running testpipes, are you running rear O2s or not?
O2: Sensor Simulator (Updated)
O2: When you guys log block 031 for O2 voltages do you look at?
O2: Where do I get the tool to remove O2 sensor?
O2: Which o2 sensors do i need to replace?
O2: X-Post from the A6/C5 Forum - Which O2 Sensor Simulator do I need? LanceEagle are you out there?
Sound: Clips
Sound: Does anyone have any first hand experience between the sound levels of a Milltek 3" Single vs. The Borla
Wrap the Evap Tube 
Exhaust: AWE twin 1, twin 2, milltek super dual, milltek 3", apr stealth, apr srt, asp true dual
DP: downpipe heat shields... yay or nay?
O2: What would be the most obvious sign that a primary O2 sensor is bad beyond a CEL?
O2: What logs should I run to check if O2s are good/bad?
O2: AntiFoulers: 19/32 too big to drill out AntiFoulers? Rips them in half... Help?
O2: Is there anyway to tap into the factory EGT sensors for Zeitronix?
Exhaust: is anyone running stock exhaust clamps with there asp dp's?
WB: People who have ZEITRONIX WB installed... why do you have to tap the speed sensor and TAP sensor
WB: I just hooked my new WB (Zei something) and here it is with my o2 reading