I have been having some problems with my idle lately. It will become very weak after depressing the clutch quickly, typically after briefly being in gear (like in traffic). It will drop to 200-400 and then bounce back after several seconds. The odd thing is when I log this, the O2 feedback is 0 during this time. Also the idle it a bit erratic most of the time. It goes back and forth from 800-1100 within 5s or so.
What do you guys think? O2 sensor going bad??

 

I am having some of those interesting issues at idle as well. One suggestion on logging, check the ground that is next to the tactrix port or OBD2 port on the car, its under the dash towards the stereo. I only say this, for when I log, sometimes I am missing a good chunk of my log as though signal is dropped. EVO scan reads zeros or infinity in some logs if no signal or eratic signal is detected. Don't quote me, just my observations over the last 2 months. Either way, back to the ground, I noticed I have like 10 things trying to ground to this point...

Electronics 101, bad ground signal leads to bad signal, leads to eratic logging. I am fixing my ground and hoping to solve some of my logging issues, to catch what we both are seeing there in the idle situation.

Oh and finally relavance to the situation, my WideBand grounds at this point... bad ground, bad A/F reading.

Good luck.

 

First ajust your BISS (SAS Screw), then try adjusting your desired initial ISCV position tables if things are still bad.

With aftermarket intakes this is a common problem because of the way the MAF "sees" air at lower hz. Air from the BOV can also get pushed back through it causing over-metering and other problems.