Just started up the engine for the first time and the aem afr is reading 17.1 and then going off the chart and staying . Worried that something bad might happen if i let it idle like this. I only ran it for about 30 seconds twice. its an open downpipe and the afr sensor is sitting about 10in away from the outlet. im using s300 on a basemap for now until i get it tuned. is this normal, should i let it warm up with this afr so i can check if there any leaks and see if everything else is working fine?

 

Nothing bad can happen at idle. If its too lean it will stall. Just increase the cold start enrichment values.

 

Just add some fuel to the low cam map. It's only going to get leaner as it warms up. You have everything sitting in front of you so you might as well learn to use it.

 

you are probably getting some false readings from the sensor being close to the end of the down pipe as well.

 

I'm getting the same lean cold start idle using s300 too. then after engine is warm is drops to high 17's low 18's. Cruising afr is 14-15 in vaccum and as soon as i hit boost its a steady 11.5-12.5. Just my cold start i was worried about. But if no harm at idle i guess im fine too. Getting mine dyno'd next month. my wideband is about 20'' away from turbo.

 

Some times the sensor has to warm up before it starts reading correct readings.
Also fuel trims and cold start tuning may need a looking at.

My car use to start up and lean out for 30sec would bog if i try to drive it.
But since i reworked the tune all is fine now.