Ltrim's 25% at idle???
 

I have the usual head/cam/intake and upgraded inj.'s mods. I keep throwing P0171 & 174 lean bank 1 & 2 codes. So I throw ATAP on and find that my idle is at 25%(super lean).

At one point it went to 9.4% and stayed there for a while and then went back up. My MAF rate was .96 at idle. Misfires on cyl.'s ranged from 1-10 on all at idle and went away with higher rpm. No knock retard at all.

Ed Wright did the PCM could he have deleted the Knock Sensor? Looks like a vaccum leak, but where do I start now? Thanks

Doug
00 Pontiac

Re: Ltrim's 25% at idle???
 

what type of m air meter are you running. Last year with ported ends mine would show 25.

Re: Ltrim's 25% at idle???
 

MAF is an 85mm SLP. I didn't throw any codes with this MAF before h/c mod's either. <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />

Doug
00 Pontiac

Re: Ltrim's 25% at idle???
 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Doug Tschantz:
<strong>I have the usual head/cam/intake and upgraded inj.'s mods. I keep throwing P0171 & 174 lean bank 1 & 2 codes. So I throw ATAP on and find that my idle is at 25%(super lean).

At one point it went to 9.4% and stayed there for a while and then went back up. My MAF rate was .96 at idle. Misfires on cyl.'s ranged from 1-10 on all at idle and went away with higher rpm. No knock retard at all.

Ed Wright did the PCM could he have deleted the Knock Sensor? Looks like a vaccum leak, but where do I start now? Thanks

Doug
00 Pontiac</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I would not doubt that knock was turned off plus shutting down the knock DTC codes for I have seen this with others I have helped who had that vendor's changes and then they went to LS1edit, so I have seen his changes.

If you feel there is no air intake or injector problems and the O2s backup what the LTFTs are saying then the PCM calibration is incorrect for idle conditions and he simply copied the high octane timing tables into the low octane timing table.

Do idle scans with engine hot, cold A/C off and then the same but with A/C on and see if there is any difference.
Also with scanner see what the injector pulse width is during those idle recording.