call me stupid-im opening myself up for some comments now lol-but if u have a full de-cat ur car wont pass an MOT-i know at MOT time u can stick ur centre section back on for day etc but what if during year u get pulle dup in a road side check by pc plod and they check emmisions plus if ur car is illegal cos of its emmisions will this invalidate ur insurance-please could do with an honest informed answer as at mo i have a downpipe back de cat exhaust but dont want to risk my insurance etc just for a bit more noise and power

Chris will answer this being plod but as far as i am aware its different. Insurance cover the car as long as mods are noted by them and they cover them in the event of an accident.

If the police do an emissions check in the side of the road that impact is 2 fold depending on them. Chris will correct me but when they did it in Bristol People got a defect report chitty and told to get it sorted in 7 days..ie replace the cat - get chitty signed and then put decat back on....But heard now that the police can impound the car? Not sure if that was care mungering but how else are you supposed to get it sorted if the car is impounded...????

Any info Chris???

I don't think they can do anything right there, you should have the chance to get it sorted (e.g. 7 or 21 days). Otherwise you'd get people being fined/impounded when they genuinely don't know their standard car's cat has failed. Most people only find out their cat has failed at MOT time, it's unrealistic to expect people to check the emissions every week just in case!

Of course having removed the cat intentionally is a different story, not sure if they can take a different course of action. Personally I'd just leave the centre cat installed, it usually ain't enough to pass emissions but a visual check will show them you still have a cat, and it makes very little noise or power difference - the downpipe one is much more important to remove.

If you get pulled, ask for a defect rectification notice - you have to take the cat to an MOT station to get a signed thing to prove that it is still legal, IIRC within 7 days.

Or fit a sports cat. Power Engineering do sports cat centre section, several people do sports cat downpipes. I have an APS system w/sports cat, and the figures I get are well up there with other people running full decat. Unlike them, I should be able to pass emmissions tests (never proved this as the car is 18 months old)