Severe Engine Miss

[lennyrebel]

Help .Today on the way to work my o6 H2 showed service engine light. OnStar said drive slowly to dealer la la la. I have about 5000 miles on truck and this is second occurence. First time truck was about a week old when said same thing. Onstar says it is a severe engine miss. Last time they said bad plug, but it shouldn't be fouling plugs at 5k miles. This is not a 2 stroke outboard. Any ideas or thoughts? I'm on my way to dealer tomorrow. Thanks Lennyrebel

[GLBLWARMR]

There are a lot of things that it could be. Could be a bad plug or plug wire. One of the plug wires might not be on tight. The electronics that control the firing could be screwed. Let us know once it is fixed.

[H2 Bill]

What's the verdict?

[lennyrebel]

Okay--tech jargon 9472 OBD2 CODE PO300 [9999] missfire happens at 65 kil/hour [35mph] most collected on cyls 5+7 Replaced 5&7 sparkplugs and clear DTC. So thats the verdict, first time it was one sparkplug at about 500 miles. This time 9400 kms about 5500 miles. No other info from dealer, anyone else have any strange occurences like this? Regards The Rebel

[lennyrebel]

I'm Wondering -are they platinum plugs in the 6 litre engine? I've never experienced this problem with my Avalanche that I drove 4 years. Service engine light never came on. Yukon before that I drove 9 years and only saw light twice. Any advice? Regards The Rebel

[ssgharkness020147]

Does the H2 have a EDIS system?