Throwing Codes

[BUMMER]

I guess I have no luck with cars. I just purchased a 2003 H2 with 73000 miles. I was driving on the highway and the Check Engine light came on. My mpg won't do any better then 8.6 !!! I took it to my mechanic and he pulled two codes
P0300 misfire
P0430 Catalytic converter, I believe on the passenger side

Are these codes directly related to one another? If anyone here has experienced these same codes what were your solutions?
Any help is greatly appreciated, thank you

[Hummeron37s]

Most likely a bad cat. I threw a p0300 multiple misfire when my cat was bad. I bought 2 magnaflow hiflow cats from amazon for $75 each and had the muffler shop cut the old ones out and weld the new ones in for $200. Never got the code again and still pass NY inspection with flying colors.

[HumminNBoatin']

Most likely a bad cat. I threw a p0300 multiple misfire when my cat was bad. I bought 2 magnaflow hiflow cats from amazon for $75 each and had the muffler shop cut the old ones out and weld the new ones in for $200. Never got the code again and still pass NY inspection with flying colors.


Totally Agree!

[BUMMER]

Thanks, I hope that is all there is to it. Did you replace your O2 Sensors as well? Besides the P0300 code, did your H2 throw any other ones?