Downpipes
Do O2 Sensor Spacers Really Work?
O2 sensor spacers can change how a sensor reads exhaust flow, but they are not a guaranteed fix. Learn the risks before buying.
Technical guides
Guides
Fitment, materials, dyno data and tuning answers from the people who build the parts. Written by AZ Motorsport in Québec.
DownpipesWhat Are Catless Downpipes?
Catless downpipes remove a catalytic converter, which can affect sound, smell, codes and legality. Learn what to check before buying.
DownpipesWill an O2 Sensor Spacer Pass Emissions?
No, an O2 sensor spacer will not automatically make a car pass emissions. A pass depends on the vehicle, catalyst, codes, readiness status, inspection...
DownpipesHow Much Is an O2 Sensor Spacer?
An O2 sensor spacer is usually a low cost part, but the real cost is diagnosis, installation and the risk of buying the wrong...
DownpipesAre O2 Sensor Spacers Legal?
O2 sensor spacers are not automatically legal or illegal in every situation. Use this guide to check emissions equipment, diagnostics, local inspections, and downpipe...
DownpipesDoes a Stage 1 Remap Affect Emissions?
A Stage 1 remap can affect emissions depending on software, fuel and parts. Learn what to check before changing the tune.
DownpipesWhy Is Car Tuning Illegal?
Tuning laws depend on emissions parts, noise and where you drive. Learn what can make a tune illegal before changing your car.
CanadaAre Downpipes Legal in Canada?
Downpipe rules depend on emissions parts, noise and province. Learn what to check before you buy or book an install in Canada.
DownpipesWhat Is a High-Flow Cat?
A high-flow cat is a less restrictive catalytic converter. Here is what that means for sound, smell, check engine lights, legality and tune planning...
B58B58 Gen 3 Downpipe Checklist: M340i, M440i, Tune and Fitment Questions
Shopping for a B58 Gen 3 downpipe? Use this M340i/M440i checklist to confirm Gen 1 vs Gen 2 vs Gen 3 fitment, catted-vs-catless choices,...
DownpipesMcLaren 600LT/675LT Downpipes vs X-Pipe Exhaust: Tune, CEL and Fitment Checklist
Compare McLaren 600LT/675LT downpipes with a 600LT X-pipe exhaust by sound, tune/CEL planning, catted-vs-catless choice, fitment checks and Quebec install questions.
8VAudi RS3 Downpipe Install Cost, Tune and CEL Checklist: 8Y/8V Buyer Questions
Pricing an Audi RS3 downpipe install? Use this 8Y/8V checklist to plan quote factors, tune/CEL risk, catted vs catless choices and fitment before booking.
