Service Engine Soon Light came on??

[PonyTrader]

Last night i got the service engine soon light come on. So today I went to Auto Zone to get a free diagnostics. They got 2 reads here they are:


Code: PO430
The PCM has determined that the catalyst system efficiency for bank 2 is below threshold for the current engine operating conditions. (Bank 1 identifies the location of cylinder #1, while bank 2 identifies the cylinders on the opposite bank)

and...

Code: PO305
The PCM has determined that a misfire has occurred in cylinder #5.

10 days ago i got BBK off-road xpipe with flowmasters put on with MIL Eliminators. Anyone know what might be wrong?

 

[biglar5.0]

the 0430 is the o2 sensor, it happened to my car.
The other ??? did you wash the engine recently?

see ya

 

[Mike97gt]

the p0430 code is most likely caused by a bad MIL eliminator.. this happens a lot thats why I like to shut it off in the tune better...


and the misfire most of the time is caused by a bad plug and or coil