decat problem

hole in decat....the bracket on the decat has came loose and broke off the decat.. i patched it up and took it off the type r and swoped over the decat of the wagon....the good decat is now on the type r..and the decat with the hole patched is on the wagon...if the hole in the decat was not sealed correctly would this cause a problem with the boost...the wagon will only go to 4500rpm them it back fires..if i feed the revs in slow it will reach 5-6000rpm then do the same thing..i am getting a check engine warning light..if i cansel it out....the car will run perfect for 2-3 miles the do it again...the thing is drinking petrol now...i will be selling the car as soon as i get the type r back,and i need to get it sorted...would putting a standered exhaust back on be the best way to sort it out....any help welcome...

if it allready had a decat and was running ok, i doubt changing to another decat would cause a problem. what fault code is it showing

showing check engine code,i just wanted to know if a hole in the decat would cause this problem,iv ran my course with it,il get it to someone who knows what there at and get it sorted,

sorted,fitted cat back on with exhaust i got of jomo eng...still didnt fix the problem,after gar_bandit spending a few hours at it..turns out there were crossed wires at the ecu..shes 100% now

wonder why it didnt set off the cel before , were they croosed from factory. or was someone at it