My cel light came on while driving my 96 lx. this car was sitting for a while before i had purchased it . i pulled the codes p0401 and p0430. after looking at the EGR, it was gunked up with carbon. the hose is very hard to get to so i dont know how i can clean that. After cleaning it out the car has run better but i hear a water sound where the pass side cat is while im driving. can these codes be related. any suggestion?