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Car was tuned before the header install and fuel trims were within 2-3%. After the headers, his fuel trims are about +20% at idle which gradually go to 0 or close to as load and rpm increase. I'm assuming the issue lies in the O2 transport delay. What do you guys think?
More than likely. Similar discussion in this thread:Quote:
Originally Posted by GPGTP
http://www.hptuners.com/forum/showth...ng-idle-hiccup
Has the car been driven around a bit after the install to allow for adaptive learning a shot at it?
Yea, he's been driving for about 2 weeks now. Also, threw a P0059 code. The more I think about it the more I think I need to put more into the heater duty cycle. My theory is: since the exhaust is cooler at idle it would explain why the correction is the greatest at that point but then tapers closer to zero as exhaust flow increases. I'm going to add a little to the heater duty cycle and see what happens, if nothing then I'm pretty sure it's the transport delay. Definitely not a sign of extra scavenging as the difference would be greater as exhaust flow increases...opposite of what I'm seeing. I'll let you know what I find out