01 5.3 P0300 after changing plugs/wires

[TheEnder53]

Hello all,

I replaced the plugs/wires on my 5.3 as it was stumbling sometimes at idle with the AC on. After replacing the plugs, with AC Delcos, and with new plug wires, i am getting a P0300 that will not go away.

The old plugs were severely worn with the middle electrode almost completely gone. Any help?

 

[Doubeleive]

Hello all,

I replaced the plugs/wires on my 5.3 as it was stumbling sometimes at idle with the AC on. After replacing the plugs, with AC Delcos, and with new plug wires, i am getting a P0300 that will not go away.

The old plugs were severely worn with the middle electrode almost completely gone. Any help?

double check your work, where were the plugs sourced from? there are tons of fake acdelco's on the market which can be a issue

 

[strutaeng]

It sounds to me like maybe the code was already set prior to the replacement of the plugs? No?

What is the history with the truck? Was it running well at some point? Did you just buy it? Any background or context helps.

 

[Marky Dissod]

Which coils is your 5.3L using?

 

[Scottydoggs]

have to ask if you were using a real spark plug socket? if not you may have cracked a plug or two.

 

[TheEnder53]

Apologies for lack of response, had to deal with some family issues.

The truck was running fine before. After some more diagnosing i fixed it. The plugs i put in were not good and once i dropped in some (dealer) sourced AC Delcos the engine immediately started to run better than it did when i bought it. So smooth you can’t tell its on now.

 

[TheEnder53]

have to ask if you were using a real spark plug socket? if not you may have cracked a plug or two.

That was another issue too. The plug socket i used didn’t have an insulator or rubber part because it was quite old. I got a new one.

 

[TheEnder53]

Which coils is your 5.3L using?

I am pretty sure they are round coils. Starts with a 190.

 

[afpj]

The truck was running fine before. After some more diagnosing i fixed it. The plugs i put in were not good and once i dropped in some (dealer) sourced AC Delcos the engine immediately started to run better than it did when i bought it. So smooth you can’t tell its on now.

Where did you get the first set of ac delco plugs from?

 

[TheEnder53]

I

Where did you get the first set of ac delco plugs from?

I got them from Oreillys.