On this page we answer some questions regarding the use of aftermarket exhausts on UK roads and some basic installation advice.
Can I remove the Db Killer?
Some of our catbacks come with db killers installed in the tailpipes. These can be removed if you want a louder exhaust. To do this you need to first remove the retaining bolt(s) and then insert a slide hammer into the tailpipe and work it out. It’s unlikely you will be able to remove the db killer until the exhaust is mounted on the car and they are pressed into the tailpipe so do require some force to remove and are can be difficult to reinstall.
The exhaust is louder than I had wanted, can I retro fit a dB killer?
Almost all tailpipes can have a dB killer installed and in most cases it will eliminate any drone inside the car.
Single skinned tailpipes are the easiest to fit a dB killer to, you just need to measure the ID of the tailpipe and order the correct size. Then when it arrives put it in the tailpipe and secure with a couple of bolts, you might need to drill holes for these.
Acoustic type tailpipes with 2 skins are more difficult to fit a dB killer to, with these you need to measure the ID of the tailpipe like with the single skinned and order the correct size. Then when it arrives put the dB killer in the tailpipe and drill a hole through both layers of the tailpipe and the dB killer the correct size for the retaining bolt to be used. Once this has been done open the hole up on the outer layer of the tailpipe so the head of the bolt will go through and the tool that will be required to hold the bolt while tightening. Using a cap head bolt is recommended to keep the outer hole as small as possible. Now you can install and tighten and the tailpipe won’t crush.
Gasket installation best practice.
The gaskets we supply are best fitted with a jointing compound. We recommend the use of high temperature RTV silicone gasket making compound on the gaskets. Ensure the mating surfaces are clean from dirt, corrosion and oil. Cover the gasket with a thin layer of the silicone and bolt together. Follow the instructions on the packet for a curing time.
Tailpipe past the rear bumper?
The tailpipe of the exhaust must not protrude past the rear bumper and must not pose a danger to a pedestrian.
How loud is too loud?
Current UK laws do not permit the use of any exhaust on a road going vehicle that produces a higher dB output than the exhaust that was fitted to the vehicle at time of manufacture.
Can I use a decat?
No, even if the car was made before catalytic converters were mandatory in 1992, if the car was fitted with it from factory it needs to stay on the car. It is illegal to remove any emission control device/component from a road going vehicle. This also remains true if the vehicle has multiple catalytic converters, they must all stay fitted to the vehicle even if you could technically remove one of them and still pass the MOT emissions test.
How about a sports cat?
Sports cats are only permissible on UK roads if they carry the correct Euro spec for the model of the vehicle and have the codes to prove this stamped into the side of the catalytic converter itself.
Can I remove the DPF?
No, if the car was fitted with it from factory it needs to stay on the car. It is illegal to remove any emission control device/component from a road going vehicle. They must stay fitted to the vehicle even if you could technically remove it and still pass the MOT emissions test.
Will the car need a remap?
This is a question that is very difficult to answer. For a catback installation usually a remap isn’t required. Anything other than this and a remap is usually advisable to ensure you take advantage of the extra flow the exhaust will have. However this varies from car to car and we always advise to take the car to a professional tuner, even better if they are a tuner that specialises in your model of car.