P0300 code after replacing parts

[MalcDogg]

I scan it and it keeps saying P0300 check cats O2 sensors

 

[Dustin Jackson]

@MalcDogg Might be worth installing some of your old parts but a p0300 code is for a random misfire, it looks like your emission monitor for the o2 sensors isn't set yet so that could indicate a problem with the cats or O2 sensors.

I would start with a compression test and then maybe install your old O2 sensors?

 

[MalcDogg]

@MalcDogg Might be worth installing some of your old parts but a p0300 code is for a random misfire, it looks like your emission monitor for the o2 sensors isn't set yet so that could indicate a problem with the cats or O2 sensors.

I would start with a compression test and then maybe install your old O2 sensors?

I think I may have figured this out but because of rain and no garage I’ll have to wait

I noticed 2 of the valves is not flushed with heads and notice some marks on the top of the pistons it’s dumping oil in the cylinders causing the misfire and blue smoke on start up so I think I’m gonna remove the heads once more and address them valves look like I’ll be replacing all the valve and the components

 

[Dustin Jackson]

@MalcDogg Sounds like could be using too long push rods. Sounds like a strange situation

 

[MalcDogg]

Well here’s an update

Went back into the engine replaced the valves and am the seals everything seems to be working fine a get a misfire then it goes away a lot of smoke coming from the tail pipe when I sit and then take off seems like it’s burning away the carbon build up from me cleaning the heads so now I think everything is good so far

 

[OR VietVet]

Well here’s an update

Went back into the engine replaced the valves and am the seals everything seems to be working fine a get a misfire then it goes away a lot of smoke coming from the tail pipe when I sit and then take off seems like it’s burning away the carbon build up from me cleaning the heads so now I think everything is good so far

WHAT does this mean? It is jibberish.....When you get old, like me, I need punctuation and sentences that end and start. Sheesh...

 

[Dustin Jackson]

@MalcDogg something doesn’t sound right man you shouldn’t be having misfires and smog coming out the tailpipe. If it quit happening and isn’t happening anymore that’s fine but if you continue to have that problem that’s not right. I had my heads redone last year with a wire wheel and never had a lick of what you’re describing

 

[swathdiver]

When you pulled the heads the 2nd time, did you use all new bolts and head gaskets? You mentioned using ebay parts, are they genuine GM?

Are you doing an AFM delete or keeping it original? It is SOP to replace the VLOM as it is this component that fails and ruins the lifters most often.

 

[Geotrash]

Well here’s an update

Went back into the engine replaced the valves and am the seals everything seems to be working fine a get a misfire then it goes away a lot of smoke coming from the tail pipe when I sit and then take off seems like it’s burning away the carbon build up from me cleaning the heads so now I think everything is good so far

What color is the smoke? Blue = oil. White = coolant.

 

[MalcDogg]

What color is the smoke? Blue = oil. White = coolant.

Blue smells like oil