I have a AQY engine which to the best if my knowledge is completely standard, the only mods I know of are a BMC air filter and a milltek 63mm exhaust. the car has always had a little pop on over run more noticeable when down shifting as approaching a set of lights for instance. Until very recently it used a standard exhaust, but that finally gave in and I had a 2 1/2 inch milltek system which I bought for a V6 conversion, that might eventually happen at some point. now the pops are pretty loud, I also notice yesterday doing some acceleration pulls yesterday there is also some ‘popping’ under heavy acceleration. I wouldn’t say the car drives any different, it’s just noisier. It occasionally throws a engine light, warning of ‘main catalyst efficiency below threshold’ but I can drove it for months, without it coming back then it will randomly appear! Normally if I am driving gently, with low throttle openings. Which doesn’t happen often. any thoughts have I got an underlying issue? The car did 200 miles yesterday averaged 36 mpg on the dash which is about normal.
Can’t seem to do videos from my phone.. https://m.facebook.com/groups/5133984559?view=permalink&id=10158817508864560
