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Audi C4 S4 Quattro 20v T Engine Emission Parts

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Innovate LC-2 Wideband O2 Controller Kit

ES#4809696 - 38770 - Innovate LC-2 Wideband O2 Controller Kit - Includes Lambda cable & 8-foot sensor cable. - Innovate Motorsports - Audi BMW Volkswagen Mercedes Benz MINI Porsche

Includes Lambda cable & 8-foot sensor cable.

Brand:
Innovate Motorsports - Corporate Logo
ES#:
4809696
Mfg#:
38770
In Stock at Vendor
$212.99 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

APR Universal Oil Catch Can - AN Fittings

ES#4487795 - MS100218 - APR Universal Oil Catch Can - AN Fittings - Universal/Service part for APR's MS100199 full catch can system - APR - Audi Volkswagen Porsche

Universal/Service part for APR's MS100199 full catch can system Call In Or Chat For Best Price! 5X Entries For Our 25th Anniversary Sweepstakes!

Brand:
APR - Corporate Logo
ES#:
4487795
Mfg#:
MS100218
Ships on Aug 26, 2026
ON SALE! SAVE 10%
$234.99

This product was last offered at the strikethrough price on
07-31-2026

$211.45 USD
Free Shipping
This product is lifetime replacement eligible Lifetime Replacement

Thin Wall Oxygen Sensor Socket

ES#4001177 - CTA2064 - Thin Wall Oxygen Sensor Socket - Out of space? Use this thin wall socket. - CTA Tools - Audi BMW Volkswagen Mercedes Benz MINI Porsche

Out of space? Use this thin wall socket.

Brand:
CTA Tools - Corporate Logo
ES#:
4001177
Mfg#:
CTA2064
In Stock
$17.85 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

Catch Can Breather Kit

ES#3447989 - 034-101-1001 - Catch Can Breather Kit - The ultimate breather can kit for the C4 AAN S4/S6, everything needed for a clean, OEM-type conversion - 034Motorsport - Audi

The ultimate breather can kit for the C4 AAN S4/S6, everything needed for a clean, OEM-type conversion

Brand:
034Motorsport - Corporate Logo
ES#:
3447989
Mfg#:
034-101-1001
Ships in 2 Business Days
$385.00 USD
Free Shipping
This product is lifetime replacement eligible Lifetime Replacement

Pressure Control Valve (PCV)

ES#2631446 - 034129101B - Pressure Control Valve (PCV) - Located on the turbo inlet pipe. 19mm - Vaico - Audi Volkswagen

Located on the turbo inlet pipe. 19mm We Price Match - Give Us A Call or Chat!

Brand:
Vaico - Corporate Logo
ES#:
2631446
Mfg#:
034129101B
In Stock
$34.99 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

Oxygen Sensor Socket - 22mm

Properly remove stubborn o2 sensors.

Brand:
Hazet - Corporate Logo
ES#:
4490396
Mfg#:
4680-1
Ships in 1 Business Day
$118.99

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

$115.99 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

Oxygen Sensor Thread Chaser

ES#4001163 - CTA2068 - Oxygen Sensor Thread Chaser - Remove rust and dirt for easy installation with this tool - CTA Tools - Audi BMW Volkswagen Mercedes Benz MINI Porsche

Remove rust and dirt for easy installation with this tool

Brand:
CTA Tools - Corporate Logo
ES#:
4001163
Mfg#:
CTA2068
In Stock
$11.41 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

ECS Catch Can O-ring

ES#3097721 - N1.50X051 - ECS Catch Can O-ring - Replacement ECS catch can O-ring - ECS - Audi BMW Volkswagen MINI

Replacement ECS catch can O-ring 10X Entries For Our 25th Anniversary Sweepstakes!

Brand:
ECS - Corporate Logo
ES#:
3097721
Mfg#:
N1.50X051
In Stock
ON SALE! SAVE 25%
$5.99

This product was last offered at the strikethrough price on
06-13-2026

$4.49 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

IE Vent To Atmosphere Billet Catch Can - Universal Fitment

ES#2794762 - IEDIYUU18 - IE Vent To Atmosphere Billet Catch Can - Universal Fitment - Prevent crankcase oil fumes from condensing and filling your intake piping, turbo piping, intercooler, intake manifold, and breather system - Integrated Engineering - Audi BMW Volkswagen MINI

Prevent crankcase oil fumes from condensing and filling your intake piping, turbo piping, intercooler, intake manifold, and breather system 5X Entries For Our 25th Anniversary Sweepstakes!

Brand:
Integrated Engineering - Corporate Logo
ES#:
2794762
Mfg#:
IEDIYUU18
Ships in 4 Business Days
$186.99 USD
Free Shipping

Oxygen Sensor Wrench 3/8" drive

ES#2949705 - SLY88750B - Oxygen Sensor Wrench 3/8" drive - O2 Sensor Socket - Schley - Audi Volkswagen Mercedes Benz MINI

O2 Sensor Socket

Brand:
Schley - Corporate Logo
ES#:
2949705
Mfg#:
SLY88750B
Ships on Aug 18, 2026
$59.99 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

Oxygen Sensor

ES#3333 - 13957 - Oxygen Sensor - Direct fit with correct plug & wire length, not a universal sensor - Bosch - Audi Volkswagen

Direct fit with correct plug & wire length, not a universal sensor 2X Entries For Our 25th Anniversary Sweepstakes!
We Price Match - Give Us A Call or Chat!

Brand:
Bosch - Corporate Logo
ES#:
3333
Mfg#:
13957
Ships in 1-2 days
$102.99 USD
Free Shipping
This product is lifetime replacement eligible Lifetime Replacement

Universal Oxygen Sensor Bung - Priced Each

ES#5051 - ATP-FLS-022 - Universal Oxygen Sensor Bung - Priced Each - Stainless steel weld-in nut for any O2 sensor - ATP - Audi BMW Volkswagen

Stainless steel weld-in nut for any O2 sensor

Brand:
ATP - Corporate Logo
ES#:
5051
Mfg#:
ATP-FLS-022
Ships in 6 Business Days
$12.95 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

Dual Drive Oxygen Sensor Wrench

ES#2944218 - LIS12390 - Dual Drive Oxygen Sensor Wrench - Tool comes with both 1/2" and 3/8" drive. - Lisle - Audi BMW Volkswagen Mercedes Benz MINI Porsche

Tool comes with both 1/2" and 3/8" drive.

Brand:
Lisle - Corporate Logo
ES#:
2944218
Mfg#:
LIS12390
Ships in 6 Business Days
$59.99 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

Hose Clamp - Priced Each

ES#469749 - N90409501 - Hose Clamp - Priced Each - Install new clamps to stay leak free. 28.6x7x.6mm - Genuine Volkswagen Audi - Audi Volkswagen

Install new clamps to stay leak free. 28.6x7x.6mm

Brand:
Genuine Volkswagen Audi - Corporate Logo
ES#:
469749
Mfg#:
N90409501
In Stock
$0.99 USD
Free Shipping
on orders $49 and up
This product is lifetime replacement eligible Lifetime Replacement

Universal Catch Can Drain Kit

ES#3543138 - 20-0024 - Universal Catch Can Drain Kit - Intuitive drain solution for most catch can applications - Radium Engineering - Audi BMW Volkswagen Mercedes Benz MINI Porsche

Intuitive drain solution for most catch can applications

Brand:
Radium Engineering - Corporate Logo
ES#:
3543138
Mfg#:
20-0024
In Stock at Vendor
$28.99 USD
Free Shipping
on orders $49 and up

More About Engine Emission Parts

Repairing failed emission components doesn't just turn off the check engine light so you can pass your local emissions test, it also improves performance and fuel economy. ECS stocks all common emission controls, from oxygen sensors to PCV valves.

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Manufacturer names and/or part numbers are used only for identification purposes.

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