Hey guys, I got my H2B civic running the other day, and my Highend header showed up yesterday morning. I installed the header and my PLX wideband which I believe is wired up correctly. I plug my laptop into my S300 and turn the key to the on position. The PLX gauge reads 14 and slowly climbs to FULL LEAN, as it should with the engine off.

Then I start the car and the gauge goes nuts. It starts to fluctuate from 14 all the way to FULL LEAN (20) and hits all kinds of random numbers in between. I'm wondering if this has something to do with my lack of exhaust and how close the O2 is mounted to the end of the header. I have nothing from the header back at the moment. I would like to run and tune the car a bit but obviously this has to be dealt with first. I'm running the S300 with the stock H22A basemap and 440cc injector size, I see no reason that should not work as a starting point for my setup. Has anyone had this problem before? I really want to get this fixed, maybe even take it for a test run this weekend!

Here's my setup, not that it matters.

Stock H22A
Highend Header
Skunk2 Intake Manifold
68mm Throttle Body
STR Fuel Rail
RC 440cc Injectors
AEM Fuel Pressure Regulator
Hondata S300

 

did you do the free air calibration of the wideband ?

 

With the engine off, the wideband is like 3-5 inches from the end of the header and I have no exhaust on it besides that header. When I turn the key to on, the gauge reads 14 and slowly turns to FULL LEAN as stated above, as it should. This is in free air, no engine running, no exhaust gases, after the car has been setting for more than 24 hours. It doesn't act up until I actually start the car, then it goes nuts.

 

is it only at part throttle, or does it do it at WOT also?

 

I'm not sure, I've been afraid to let it run very long or rev it very high due to the O2 not functioning right. I don't have the narrow band in place and if it's running lean I don't want to push it too hard. Maybe I just need to grow a pair and try it at WOT. Here's a link to what it does at idle:

http://www.youtube.com/watch?v=lHLHQ...ature=youtu.be

Poor quality but you get the idea

 

Hey guys, just an update: I ran home on my lunch break and bolted about a 12" test pipe on behind the header. I then started the car and the gauge stayed steady and slowly dropped to the rich side leveling out at about 11.4 at idle. This is obviously too rich but the gauge issue is fixed!