Cold start noise reduction

On a cold start the engine deliberately runs a retarded ignition timing and a raised
idle to get exhaust temperature up fast and light the catalyst. That is why some cars are
noticeably rougher and noisier for the first minute.

It can be softened. The trade off is that the catalyst takes longer to reach working
temperature, and cold start is when most of a journey emissions are produced.

On an early morning start in a terrace this matters to people. We will do it, and we
will tell you what it changes.

For the trade

This is one of the jobs available through our dealer file service. Send the
original read, tell us the vehicle and what you need, and the file comes back
checked. If a job carries mechanical conditions on the car, they are listed in the
coverage table below and they apply to your customer’s vehicle too.

More about becoming a JFA tuning dealer