Spark plug replacement after 10 years...
Thread Starter
Burning Brakes
Joined: Jul 2004
Posts: 768
Likes: 6
From: Newport Beach, Southern California
Original plug for 98 and 97 was Platinum AC Delco 41-931 gap .60..... in 99 GM switched to AC Delco 41-985 Iridiums gap .40 I think these newer plugs are superior that`s why the difference.
Change them, you won`t be sorry
Change them, you won`t be sorry
Last edited by 2blklt4; Jan 26, 2010 at 07:43 PM.
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Joined: Oct 2004
Posts: 73
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AC Delco
I learned this from a trusted source when I did my plugs:
The Latest GM PCM programming is to OPTIMIZE the new
AC Delco 41-985 Iridium plug.
I seem to recall reading if you got the programming for the column lock recall you have the programming for the AC Delco plug optimization.(I could be mistaken on the column lock recall being the one......memory being what it is)
The new plug should not be gapped because there is a special electro plating on the electrode that if damaged by gapping, can lead to premature wear of the grounding electrode. If the Gap is not correct you need get another plug.
I got much better results with the AC Delco plugs than the plugs(POPULAR BRAND) that I had previously installed.
The Latest GM PCM programming is to OPTIMIZE the new
AC Delco 41-985 Iridium plug.
I seem to recall reading if you got the programming for the column lock recall you have the programming for the AC Delco plug optimization.(I could be mistaken on the column lock recall being the one......memory being what it is)
The new plug should not be gapped because there is a special electro plating on the electrode that if damaged by gapping, can lead to premature wear of the grounding electrode. If the Gap is not correct you need get another plug.
I got much better results with the AC Delco plugs than the plugs(POPULAR BRAND) that I had previously installed.
Last edited by Uglymarine; Jan 26, 2010 at 08:54 PM.
