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Audi S4 Exhaust Emission Parts

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7/8"(22mm) Flexible Oxygen Sensor Wrench

ES#240942 - FO-78 - 7/8"(22mm) Flexible Oxygen Sensor Wrench - The proper tool to remove difficult-to-reach oxygen sensors - Schwaben - Audi BMW Volkswagen Mercedes Benz MINI Porsche
ECS Tuning recommends this product.

The proper tool to remove difficult-to-reach oxygen sensors 10X Entries Into Our F80 M3 Sweepstakes

Brand:
Schwaben - Corporate Logo
ES#:
240942
Mfg#:
FO-78
Ships on Dec 1, 2026
ON SALE! SAVE 25%
$48.99

This product was last offered at the strikethrough price on
05-02-2026

$36.74 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

Universal Catalytic Converter - 2.25"

ES#4005308 - 602205 - Universal Catalytic Converter - 2.25" - 2.25" inlet/outlet, 14" length of converter itself, 6" width & 4" height - Emico - Audi BMW Volkswagen Mercedes Benz MINI Porsche

2.25" inlet/outlet, 14" length of converter itself, 6" width & 4" height

Brand:
Emico - Corporate Logo
ES#:
4005308
Mfg#:
602205
Ships in 3 Business Days
$97.99 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

Remanufactured Catalytic Converter - Left

ES#2500792 - 8E0254505SXKIT - Remanufactured Catalytic Converter - Left - Price includes a $125 refundable core charge - Genuine Volkswagen Audi - Audi

Price includes a $125 refundable core charge For vehicles with automatic transmission only

Brand:
Genuine Volkswagen Audi - Corporate Logo
ES#:
2500792
Mfg#:
8E0254505SXKIT
Ships on Nov 3, 2026
$4439.99 USD
Free Shipping
This product is lifetime replacement eligible Lifetime Replacement

Locking Nut - Priced Each

ES#471981 - N91130801 - Locking Nut - Priced Each - Locking nut with flange. M8x1.25mm - Genuine Volkswagen Audi - Audi Volkswagen

Locking nut with flange. M8x1.25mm

Brand:
Genuine Volkswagen Audi - Corporate Logo
ES#:
471981
Mfg#:
N91130801
In Stock
$1.99 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

Remanufactured Catalytic Converter - Right

ES#2532864 - 8E0254554QXKT - Remanufactured Catalytic Converter - Right - Price includes a $210 refundable core charge - Genuine Volkswagen Audi - Audi

Price includes a $210 refundable core charge For vehicles with automatic transmission only

Brand:
Genuine Volkswagen Audi - Corporate Logo
ES#:
2532864
Mfg#:
8E0254554QXKT
Ships on Nov 3, 2026
$4103.99 USD
This product is lifetime replacement eligible Lifetime Replacement

Front Oxygen Sensor - Priced Each

ES#4135675 - 06E906265AJ - Front Oxygen Sensor - Priced Each - Keep your engine running efficiently - Bosch - Audi

Keep your engine running efficiently We Price Match - Give Us A Call or Chat!
Fits the left and right position

Brand:
Bosch - Corporate Logo
ES#:
4135675
Mfg#:
06E906265AJ
In Stock
$369.20 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

Self-Locking Nut - Priced Each

ES#2588753 - N90369001 - Self-Locking Nut - Priced Each - Install new hardware with your new parts. M10x1.5 - Rein - Audi BMW Volkswagen

Install new hardware with your new parts. M10x1.5 2X Entries Into Our F80 M3 Sweepstakes
We Price Match - Give Us A Call or Chat!
Used to secure the catalyst/downpipe to the turbo

Brand:
Rein - Corporate Logo
ES#:
2588753
Mfg#:
N90369001
In Stock
$4.99 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

Oxygen Sensor Tool - Angled Handle - 7/8" - Bavarian Autosport

ES#3673911 - B8800066 - Oxygen Sensor Tool - Angled Handle - 7/8" - Bavarian Autosport - Slotted, pivoting head has both hexagon and double hexagon drive. Angled handle reaches around obstructions. - Bav Auto Tools - Audi BMW Volkswagen Mercedes Benz MINI Porsche
ECS Tuning recommends this product.

Slotted, pivoting head has both hexagon and double hexagon drive. Angled handle reaches around obstructions. 10X Entries Into Our F80 M3 Sweepstakes

Brand:
Bav Auto Tools - Corporate Logo
ES#:
3673911
Mfg#:
B8800066
In Stock
ON SALE! SAVE 25%
$49.99

This product was last offered at the strikethrough price on
05-02-2026

$37.49 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

Rear Oxygen Sensor - Priced Each

ES#4069386 - 06E906265Q - Rear Oxygen Sensor - Priced Each - Fits left and right side - Bosch - Audi

Fits left and right side We Price Match - Give Us A Call or Chat!

Brand:
Bosch - Corporate Logo
ES#:
4069386
Mfg#:
06E906265Q
In Stock
$192.18 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

Oxygen Sensor - Priced Each

ES#2435 - 1K0998262AB - Oxygen Sensor - Priced Each - Keep your engine running efficiently - Bosch - Audi Volkswagen

Keep your engine running efficiently We Price Match - Give Us A Call or Chat!
Fits left and right front position

Brand:
Bosch - Corporate Logo
ES#:
2435
Mfg#:
1K0998262AB
Ships in 1 Business Day
$148.99

This product was last offered at the strikethrough price on
05-07-2026

$136.99 USD
Free Shipping
This product is lifetime replacement eligible Lifetime Replacement

Universal 4-Wire Oxygen Sensor - Priced Each

ES#2532224 - 15733 - Universal 4-Wire Oxygen Sensor - Priced Each - Four wire universal OBD-II Oxygen sensor - Bosch - Audi BMW Volkswagen

Four wire universal OBD-II Oxygen sensor We Price Match - Give Us A Call or Chat!

Brand:
Bosch - Corporate Logo
ES#:
2532224
Mfg#:
15733
In Stock
$74.99 USD
Free Shipping
This product is lifetime replacement eligible Lifetime Replacement

Catalytic Converter Install Kit

ES#2576283 - 8K0253115AKT2 - Catalytic Converter Install Kit - Contains all of the hardware you need to install new catalytic converters on your Audi - Assembled By ECS - Audi

Contains all of the hardware you need to install new catalytic converters on your Audi 10X Entries Into Our F80 M3 Sweepstakes

Brand:
Assembled By ECS - Corporate Logo
ES#:
2576283
Mfg#:
8K0253115AKT2
In Stock
ON SALE! SAVE 12%
$98.99

This product was last offered at the strikethrough price on
05-02-2026

$87.01 USD
Free Shipping
This product is lifetime replacement eligible Lifetime Replacement

High-Flow Catalyst Installation Hardware/Gasket Kit

ES#4858168 - 034-105-A015 - High-Flow Catalyst Installation Hardware/Gasket Kit - Includes everything you need to install or replace your 034Mototorsport High-Flow Catalyst or OEM Catalyst. - 034Motorsport - Audi

Includes everything you need to install or replace your 034Mototorsport High-Flow Catalyst or OEM Catalyst. 2X Entries Into Our F80 M3 Sweepstakes

Brand:
034Motorsport - Corporate Logo
ES#:
4858168
Mfg#:
034-105-A015
Ships in 1 Business Day
$160.00 USD
Free Shipping
This product is lifetime replacement eligible Lifetime Replacement

Front Oxygen Sensor

ES#3604972 - 06M906265 - Front Oxygen Sensor - Keep your engine running efficiently - Genuine Volkswagen Audi - Audi

Keep your engine running efficiently

Brand:
Genuine Volkswagen Audi - Corporate Logo
ES#:
3604972
Mfg#:
06M906265
Ships in 2 Business Days
9% off MSRP

MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.

$298.99

This product was last offered at the strikethrough price on
10-18-2026

$272.99 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

More About Exhaust Emission Parts

Oxygen sensors, catalytic converters, and other critical emissions components not only cause Check Engine Lights when they fail, but they'll also keep you from registering your car. Make sure your emissions system is functioning properly so you can continue to drive your car legally.

Let us help you find the parts that fit your Audi

ECS Tuning is not affiliated with any automobile manufacturers.
Manufacturer names and/or part numbers are used only for identification purposes.

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