i just recently put a new clutch in my 00 em1 and in the process i broke the o2 sensor on the header so before i put it back together i took the one off the cat and put it in the header and put the broken one in the cat for the time being till i get a new one could this throw off gas mileage because i burn gas like its a v8 now

 

yes. itl drive like dinosaur **** too

 

yea i figured that because i upgraded my flywheel and got rid of a/c and it still pulls the same as it did before and vtec dont sound the same eiather