vettenuts

iTrader: (4)

Just finished installing a set of Dart 205's. Car has a VHP cam which is 216/224 .551/.551 115LSA which is not too radical but is a little lumpy on idle. Had no codes prior to the heads, but now it is throwing the P0300 and when I look at which cylinder, it is all of them not limited to just one. I can't detect a misfire and the car absolutely runs fantastic from cold start to running hard. I have not yet had it tuned from the head installation, is this a normal thing to have happen?

Zymosis

iTrader: (7)

Without getting it tuned, I think the cam could cause the random misfire code, especially if you don't notice it running 'bad'.

vettenuts

iTrader: (4)

ttt-for the day

silverTA2002

iTrader: (1)

I got the same code with my heads/cam install.

Check plugs/wire just to be sure, but most likely, the cam is confusing the computer into thinking it has a misfire.

I changed the misfire parameters at idle and no more code.

If you have a misfire in higher rpm ranges, that would be a different story.

Basicaly, blame the cam, tune it out.

98A4LS1

iTrader: (1)

Could you elaborate more on how to tune it out? I'm having this problem after cam install. SES sets at idle rpms in Park, ie cold start SES comes on while car is warming up.

ringram

I agree, its the cam.

You can set the code to not report same as you do for changing maf codes to no mil or whatever. Or better than that there are a whole lot of misfire tables that you can adjust to "tune" it out.
Take a look in your tuning software. Low rpm and maybe idle misfire tables.

In efi the tables are C5601 to C5627 loads to play with there.