Anyone ever heard of them leaning out a LS1? I'm about to order some Macs with O/R pipe and have my stock cats welded in and wan't to know what to expect to happen with my AFR.

 

Your headers actually lean the car out at idle and part throttle cruzing. This causes your ltrims to compensate for this by adding fuel. Then when you go into power enrichment mode (wide open throttle) this added fuel will still be there causing your car to run rich. The only way to fix this is with a maft or preferably ls1 edit so you can adjust through the injector flow rate table and not loose timing which occurs if you skew the maf table too much.

 

LS1 jay, the further back you install those cats the more power they will allow before restricting, but they need to be in stock location to be emission legal, and to work 100% like oem. Just a heads up in case you werent thinking of that.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by LS1derfull:
<strong>LS1 jay, the further back you install those cats the more power they will allow before restricting, but they need to be in stock location to be emission legal, and to work 100% like oem. Just a heads up in case you werent thinking of that.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Hadn't thought about that, I was going to put them back a little bit, we don't have emission testing here anyway, I just wanted the cats in there to keep it quiet! I had thought about bullets, but figured cats would be even quieter?

<small>[ December 08, 2002, 07:25 PM: Message edited by: LS1JAY ]</small>