o2 Delete | Lambda Delete | CAT Delete | Slough

LAMBDA DELETE - Catalyst Solution

Decat Remap & O2 Sensor Delete – Optimised ECU Tuning for Decat & Downpipe Installations

LAMBDA DELETE - Catalyst Solution

When installing a decat pipe or high-performance downpipe, the engine control unit (ECU) detects a reduction in catalytic converter efficiency, triggering an engine management light (EML) and storing a P0420 or P0430 fault code. These codes indicate that the vehicle’s second lambda (O2) sensor is detecting an inefficiency in the exhaust system, which can cause issues such as:

– Persistent warning lights on the dashboard

– Poor throttle response due to incorrect ECU adjustments

– Engine running in limp mode, limiting performance

– Potentially failing emissions checks

At Onyx Performance, we offer specialist ECU recalibration to disable the secondary lambda sensor’s function, allowing your vehicle to run optimally with a decat or sports downpipe. Our custom tuning solutions ensure a seamless integration with your modified exhaust system, preventing fault codes and maintaining smooth operation.

Why Choose Onyx Performance?

As Seen on Carwow

We’ve been proudly featured on Carwow – a testament to the quality, professionalism, and performance-focused results that set us apart. Watch our feature here to see us in action.

Expertise You Can Trust

With years of experience and deep technical knowledge, our team understands performance vehicles inside and out – from custom remaps to high-end servicing.

Advanced Workshop & Tools

We operate from a state-of-the-art facility in Slough, equipped with cutting-edge diagnostics, dyno testing, and industry-leading tools for accurate, high-quality work.

Tailored Solutions for Every Vehicle

We don’t believe in one-size-fits-all. Every car gets a bespoke approach, ensuring the best results whether it’s a remap, upgrade, or routine service.

Trusted Nationwide

Performance enthusiasts from across the UK come to Onyx because they know they’ll receive premium-quality workmanship, careful attention to detail, and honest advice.

Complete Care, All in One Place

From tuning and servicing to tyres, trackers, and immobilisers – we offer a full suite of services under one roof, all with a strong focus on safety, reliability, and top-tier customer support.

Why is an ECU Remap Essential After a Decat?

Most petrol vehicles are equipped with a primary and secondary lambda (O2) sensor. The primary sensor monitors air-fuel ratios, while the secondary sensor ensures the catalytic converter is working efficiently. When a decat pipe is installed, the second sensor detects that emissions are outside expected parameters, leading to an engine warning light and stored fault codes.

An ECU remap will:

– Disable the second lambda sensor to prevent EML and fault codes

– Optimise fuel delivery for improved throttle response

– Prevent limp mode caused by emissions-related faults

– Ensure the engine runs efficiently with an aftermarket exhaust

For vehicles fitted with a high-flow sports cat instead of a full decat, we can also recalibrate the ECU to align with the reduced emissions restrictions while keeping the system functioning as intended.

Customer Reviews

    
 
 
       Posted on Google  
   
   Anil Soni 
 
 
 
 Trustindex verifies that the original source of the review is Google. Thank you guys for your professional, dedicated and honest opinion. You made my day by fixing my son's car so he could use it for DoE at very short notice. Max and Kay were brilliant and I would definitely recommend this garage as a organised and trustworthy business. Keep up the good work.
  
 
      Posted on Google  
   
   subin pradhan 
 
 
 
 Trustindex verifies that the original source of the review is Google. Took my BMW 440i to install downpipe and mid pipe. Top guys with good service and reasonable price. Will be going back for more work done.
  
 
      Posted on Google  
   
   J JareCki 
 
 
 
 Trustindex verifies that the original source of the review is Google. I just done Stage1 in my audi s3, car drive superb, excelent service, thanks Ben,Sam and Onyx team! Brilliant work
  
 
      Posted on Google  
   
   Dan May 
 
 
 
 Trustindex verifies that the original source of the review is Google. Honest and knowledgable! Rare these days - saves me hundreds by checking my Golf R properly. Will only use these guys from now on
  
 
      Posted on Google  
   
   Darren Dawes 
 
 
 
 Trustindex verifies that the original source of the review is Google. I took my jaguar xfr to these guys for a re map . Excellent service. They could not have been more helpful. Very knowledgeable they definitely know what they are doing. If your looking for a re map I would highly recommend you speak to them.
  
 
      Posted on Google  
   
   Hana 
 
 
 
 Trustindex verifies that the original source of the review is Google. I was recommended Onyx to get my diamond-cut alloys refurbished. I am located an hour away but the recommendation was important so decided to leave my car with these guys. First impressions, the team were very polite, friendly (Essan, Ben and the guys that actually did the refurb in the intense heat) The prices were competitive. And the quality of work was super. There was slight miscommunication post the sale (which happens) but I was pleased they resolved this to my satisfaction. One idea I would suggest is advising the customer 'before' the work starts that the TPF valves may need replacing so we have the option to decide whether to do it whilst the wheels are off anyway rather than post refurb to avoid scratching the newly done alloys. Otherwise happy with my overall experience.
  
 
      Posted on Google  
   
   Mark 
 
 
 
 Trustindex verifies that the original source of the review is Google. Amazing service
  
 
      Posted on Google  
   
   pavan khangura 
 
 
 
 Trustindex verifies that the original source of the review is Google. The best experience ever well organised clean friendly team and the experience was amazing A big up to the whole staff.

Custom ECU Tuning for Decat & Sports Exhausts

We provide custom ECU remaps tailored to your vehicle’s modifications, ensuring the best performance and reliability. Unlike generic tuning files, our remaps are developed to work with your specific setup, whether you have:

– A decat downpipe for increased exhaust flow

– A high-flow sports catalytic converter

– A full performance exhaust system

– Turbo upgrades requiring recalibration of fueling and airflow

Every remap is developed using advanced tuning software and can be tested on our rolling road dyno to ensure optimal results.

Exhaust Upgrades & Performance Downpipes

In addition to ECU remapping, we offer a range of performance exhaust solutions, including:

– Decat downpipes for maximum exhaust flow and sound

– High-flow sports catalytic converters for improved emissions compliance

– Stainless steel cat-back exhaust systems for enhanced performance

– Resonator and muffler deletes for a more aggressive exhaust note

Our exhaust upgrades are carefully selected to complement ECU tuning, ensuring your vehicle benefits from both improved airflow and properly calibrated ECU adjustments.

Book Your Lambda Delete & Catalyst Solution in Slough

Running a decat or upgraded exhaust system? Avoid fault codes and performance issues with our lambda delete & catalyst solutions. Expert ECU recalibration for performance and modified cars. Contact our Slough tuning specialists today to book in.

5-Star Google Reviews

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Who Needs a Decat Remap?

A decat remap is essential for any vehicle that has had its catalytic converter removed or replaced with a high-flow alternative. It is particularly beneficial for:

Performance-focused vehicles

Performance-focused petrol vehicles such as Audi S & RS models, BMW M Series, Mercedes-AMG, Porsche, Volkswagen R models, and other high-performance brands

Turbocharged vehicles

Turbocharged vehicles where a free-flowing exhaust can enhance spool and throttle response

Track or off-road vehicles

Track or off-road vehicles that require a decat for weight reduction and performance gains

We also offer custom solutions for naturally aspirated engines, ensuring the ECU is correctly tuned to avoid unwanted error codes and inefficient fuel mapping.

Specialist ECU Tuning in Slough, Near West London

We are based in Slough, Berkshire, with customers travelling from across the UK for our ECU remapping and exhaust tuning services. Our workshop is conveniently located near major routes including the M25, M4, and M40, making us easily accessible from London, Reading, Maidenhead, Windsor, Ascot, High Wycombe, and surrounding areas. For those looking for specialist tuning solutions, we offer a range of services tailored to high-performance and modified vehicles. This service is sold for offroad/export use only.

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