lean afr on cold start
Thread Starter
On The Tree
Joined: Mar 2010
Posts: 112
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From: Iowa
lean afr on cold start Ok heres a quick run down. I installed a wideband lc-1 then tried to do a little tuning with hp tuners for the ve tables. I had to many different things goin on and had no time to really focus on getting the tuning done. So I flashed the previous program back in there till I have more time to work on it. That program is the stock one. The only things done to it are the skip shift delete and rear o2 delete. So what I'm noticing is that on cold starts my afr is around 17-18 idling in the drive way till it starts to warm up then drops to 14-15. I can hear the air pump running when the afr is 17-18. So I think that is why its so lean. I just wanna be sure that this is a normal thing. I do remember the afr being lean before all this at cold start but I can't remeber exactly what it was. So is this cold start afr normal?
Also I'm not running cats and if I recall the air pump is used to heat the cats at start up. I bought the headers with the emissions setup because I was originally gonna run cats but changed my mind. So can I turn off the air pump in the tune and leave it at that or do I need to completely remove it?
Thanks.
Also I'm not running cats and if I recall the air pump is used to heat the cats at start up. I bought the headers with the emissions setup because I was originally gonna run cats but changed my mind. So can I turn off the air pump in the tune and leave it at that or do I need to completely remove it?
Thanks.
Yes you can turn it off in the tune. I would also block off the ports on the headers. I went through 2 sets of factory check valves and then finally made a little plate to block them off.
