Wynns 50864 Exhaust Stop Smoke 325ml Reduce Engine Noise Improve Compression

I've used this before, Good to use a week before MOT to help get through Emissions test.It does reduce smoke but after a month sometimes I get a puff of smoke.Helps to use a Catalytic and Injector Cleaner as well.

Not too sure if it stops smoke effectively. But, it certainly makes engine run quieter.

Didn’t work for my car on boosting from turbo

will recommend

Super stuff, it really works.