Code P0304

KUALUMNUS

MEMBER
19 POSTS

Also, 1 1/2 month ago O'Reilly's sold me a Standard (brand) IAC valve; my car needs the Delphi (brand) IAC valve which I bought and installed last Tuesday. You probably know the former is always open normally (no B+ applied) and the latter is normally closed. Resetting the PCM and having my car relearn the idle and fuel trim settings today has made a huge difference for the better: smoother idle, hot idle for 20 minutes without A/C on and no P0304 code, and it seems my car's response is better (quicker). I'm very happy with my car now, Joe.

SPONSORED LINKS

Was this

answer

helpful?

Yes

Friday, June 24th, 2022 AT 5:21 PM

JACOBANDNICKOLAS

MECHANIC
109,885 POSTS

Hi,

That's good news. I'm glad to hear it's running better. If you do have a chance to check the two other cylinders' compression, let me know what it is. However, if the light is off and it is running good, it may be better to leave well enough alone.

The concern I have is the head gasket sealer that was used. It works when used correctly, but it's not a permanent fix. At least that is what I have experienced.

Regardless, take good care of yourself, and please feel free to come back at any time in the future. You are always welcome here.

Joe

Was this

answer

helpful?

Yes

Friday, June 24th, 2022 AT 8:53 PM

KUALUMNUS

MEMBER
19 POSTS

Hi Joe,

I'll likely check cylinders 5 and 6 compression by midweek next week and I'll let you know the results. Thank you for your advice and guidance Joe.

Best regards,
Jim

Was this

answer

helpful?

Yes

Friday, June 24th, 2022 AT 9:39 PM