Misfire

[d_itup]

New to the forum. I have a 2001 Tahoe 5.3 with 157,***. I started getting the P0300 code about 6 months ago, mostly when I would be coasting down a hill. I recently changed the plugs and wires and have still been getting it.

I have experienced misfire in a I4 engine and can definitely feel it. I would imagine that it is not as severe, but would you feel a misfire in a V8? I have not felt anything in regards to a misfire.

I messed around in the search and saw some information on the P0300 code being caused by a bad Cat. Does this sound like my issue, or could it be something else?

 

[dwmmatt23]

New to the forum. I have a 2001 Tahoe 5.3 with 157,***. I started getting the P0300 code about 6 months ago, mostly when I would be coasting down a hill. I recently changed the plugs and wires and have still been getting it.

I have experienced misfire in a I4 engine and can definitely feel it. I would imagine that it is not as severe, but would you feel a misfire in a V8? I have not felt anything in regards to a misfire.

I messed around in the search and saw some information on the P0300 code being caused by a bad Cat. Does this sound like my issue, or could it be something else?

P0300 is a general misfire could be caused by alot of issues. If the cats were bad you would get a P0420 or 430 and that means replace cats, trust me been there. Try running a can of seafoam through it, just saying cause if you search theres been a few members that have "seafoamed a p0300 away". I have a leaky intake manifold gasket and have gotten a P0300 code once when it was cold and stumbling, so I know it through the code cause of extra air mixing in