Subject	Gutted precats, now idle and cruise AFR is rich
Posted by	LitlElvis on July 10, 2012 at 11:38 AM
	This message has been viewed 237 times.
Message	While switching out transmissions recently I noticed the catalyst in the precats was melted and seriously damaged, so I decided to gut them out old-school-like. Upon reassembly my AEM wideband now shows the AFR has become ~1.0 to 1.5 richer during idle and cruise conditions. I tend to think that reducing an exhaust restriction would lead to a leaner condition so I'm a bit perplexed. Maybe the damaged catalyst was affecting the true reading of the O2 sensor due to the proximity in the precat? Does this change in AFR make sense to anyone?
Follow Ups	Gutted precats, now idle and cruise AFR is rich - LitlElvis 11:38:55 07/10/12 I would expect the AFR ratios to read richer since the - ForceFedTT (SoCal) 11:59:56 07/10/12 Normal. Cats mask the true AFR if your WB is post cat. (n/m) - marklar182 12:06:29 07/10/12 WB is before the catalyst, in the stock O2 sensor location. (n/m) - LitlElvis 12:43:05 07/10/12 Where are your o2 sensors mounted? - bartz32tt 13:26:55 07/10/12 No stock O2 sensors, using AEM EMS with WBO2 feedback (n/m) - LitlElvis 13:52:56 07/10/12 I have convoluted data. - RSR 12:24:49 07/10/12
Post a Followup	You cannot reply to this message because you are not logged in.