42 Draft Catless O2 Sensor Tester

  • 42 Draft Catless O2 Sensor Tester (EX-99-200)
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$45.00 $44.10
(You save $0.90)
1.00 LBS
Product is made to order. Allow up to 5-15 business days for production before product is shipped.
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VW/Audi/Porsche/BMW/MINI/Fiat/Lamborghini/Mercedes Benz Performance Parts: 42 Draft Catless O2 Sensor Tester (EX-99-200)


Product Features & Benefits

  When an aftermarket high-flow catalytic converter is used on a late model car its common to see a CEL (Check Engine Light) come and go. This CEL is usually backed by a fault code that indicates a failed cat. If your new cat is NEW, how could it have failed? Behind the scenes, the factory ECU is comparing the readings from a pair of oxygen sensors to measure the effectiveness of the cat. When a high-flow cat is used the exhaust gases are able to pass by the cat at a much faster rate, disrupting the readings. 42DD's o2 sensor tester retracts the second oxygen sensor from the direct flow of gases, restoring the balance that the ECU requires when using a high-flow cat.

  42DD O2 Sensor Tester is CNC machined from cold roll steel & grade 8.8 metric hardware. After assembly, 42DD's tester undergoes a zinc dichromate plating process which protects the tester from corrosion. Installation is plug & play. Simply thread in 42DD's tester, thread in the rear o2 sensor, and lock the tester at the desired angle.

  Strictly for use with a 49 state legal aftermarket high-flow catalytic converter such as the Magnaflow catalytic converter used exclusively in 42DD exhaust systems.  This product is not intended to and will not provide emissions compliance.  Emissions laws vary by state. Check local and federal laws before modifying your exhaust system.  Emissions compliance is the sole responsibility of the vehicles owner.

Additional Details


  We make no claims as to emission performance for street or highway use. Some equipment is not sold for street use in any state or country where state or federal regulations prohibit its use. Some items listed in the online catalog are intended for off road use and for purpose built race cars only. EUROTEK TUNING, LLC does not make any claims of street legal use of these products that are not intended for use on public roads. We are not affiliated with Volkswagen Audi Group, Porsche AG or any of their subsidiaries. EUROTEK TUNING, LLC is not responsible for errors on our website.

Product Reviews

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  1. worth every penny. 5 Star Rating

    Posted by on 1st Oct 2014

    Installed 3" exhaust and also added a o2 problem to my gti. This was the perfect fix for the problem with out a doubt.

  2. I stand corrected 3 Star Rating

    Posted by on 17th Sep 2013

    I fiddled around for awhile and after clearing the CEL three times and aiming the top of the O2 sensor to the back of my headlight. The CEL is gone.

    Much Thanks

  3. Turbo back exhaust system 3" 5 Star Rating

    Posted by on 16th Sep 2013

    Great product!!! My 1.8T VW has a short O2 wire sensor thus the product help me to conect correctly the sensor in my new 3" turboback exhaust system. In addition, the product avoid the check engine light on my car.

  4. 2.0Tfsi 2 Star Rating

    Posted by on 15th Sep 2013

    CEL from having a high flow CAT installed, bought this and the CEL light has not gone away...I shouldn't have to play the guessing game of how to position it or anything. I'm unsatisfied

  5. Did the Job 5 Star Rating

    Posted by on 14th Aug 2013

    Have a modified Mk3 GTI VR6 with a high flow cat installed. This product so far eliminated the check engine light that been a real pain for years.

  6. High Quality Product 4 Star Rating

    Posted by on 7th Aug 2013

    I rated this product 4 stars because although is built though and the craftsmanship is great. It took me many times to screw and unscrew it until my Check engine light was gone. Then a day after it was gone the light came back and has been on and off for days. I keep screwing it and unscrewing it to find the perfect position still. I have a MKV GTI with an Euro Customs Downpipe no CATs.

  7. GREAT PRODUCT 5 Star Rating

    Posted by on 12th Feb 2013

    Got this product for my 2006 MKV GTI. I bought an aftermarket downpipe from eruocustoms. A check engine light showed up so i ordered one of these and it went away.

  8. Perfect fit! Very high Quality! 5 Star Rating

    Posted by on 26th Jan 2013

    I was worried it would not fit the O2 bungs on my Audi AMB 1.8T downpipe, but it fit perfect! The spacer looks great and I never got a check engine light. I was very pleased! 42 Draft Designs is the real deal.

  9. Works great! No leaks no CEL!! 5 Star Rating

    Posted by on 9th Sep 2012

    I was very impressed with how well this works! Easy to install and got me through emissions tests with no problem! Little pricey but worth it in the end! I recommend this product to anyone with a P0420 code. I currently have an 04 VW GLI 3" catless turbo back and the 42 draft design spacer did the job!

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