War Chip Forums

General => Naturally Aspirated Tuning => Topic started by: ding on December 28, 2013, 02:49:20 PM

Title: NA m5x AFRs
Post by: ding on December 28, 2013, 02:49:20 PM
Just looking to get an idea of what people are seeing at idle.  I've seemed to get my idle under control, and I have my m52 with 21s and a 3.5 maf up and running but I'm seeing around 17.0 afr at warmed up idle.   I was running super rich with a turner chip and my 3.0 maf, but my maf might have been bad.
Title: Re: NA m5x AFRs
Post by: bmwstudent on December 29, 2013, 04:58:53 AM
When I first installed my new exhaust I had a small leak near the wide band sensor and it was causing me to have a lean reading just off idle. I fit a new clamp at the leaking joint and the problem went away. Not sure if this could be your issue but I was surprised to see that much of a change from just a leak at the header collector( my sensor is just in front of the leak 2-3"). But if it's an accurate reading I would be worried, 17.0, that's pretty lean.
Title: Re: NA m5x AFRs
Post by: millerperformance on February 05, 2014, 01:30:07 PM
17 at idle is not a big deal unless you can feel, or hear the car struggling. turn your O2 sensor off and see where AFR goes naturally. A bad O2 sensor and or O2 sensor heater relay can cause strange issues.