Ruff idle. P0300 dtc

[rkf63k10]

I know this has been answered a lot on this forum, but I thought I would ask again. (doesn't hurt) 2005 GMC 5.3l with 62k on it. At idle the CEL comes on, I check it and come up with a P0300 dtc. So I cleared it off and it stayed away for a week or so. Then just recently, I started it up, let it warm up and the CEL was back with the same dtc. It seems to run good while driving, but at idle it runs rough. I have an AEM Brute Force air system on it that has the dry air filter on it. Just wondering If I should clean the MAF and try again. I don't hear any vacum leaks and the wires look good. I also have the E3 spark plugs in it. Any more suggestions? I also would like to know what ohms the injectors need to read and how to check for a weak coil.

 

Thanks

Ron.

[txab]

You can clean the MAF. Clean the TB as well. Check fuel pressure. E3 plugs generally do not perform well according to the feedback received on this forum. Stay with AC Delco Iridium plugs.

 

To get rid of the "ruff" loose the dog.

[rkf63k10]

I was hoping someone would catch the "ruff"! I'll try all that is suggested. I might have filled up with some bad fuel too. Think I'll change back to the old plugs too.

[desrtrat]

change out the E3 plugs are known for causing misfires..also run some injector cleaner thru a couple tanks of gas..