Anyone else have this problem? I know the RSX-S folks were having issues with Hondata #4 and race headers at one point, but it seemed like that sort of died down (or maybe I quit paying attention).
Anyway, a buddy of mine started getting the "lean condition" CEL in regards to the primary 02 sensor on his Civic. He said it came on twice in the last week. He's had the DC race header for a while (a month or two, at least) and Hondata for a little while as well. I have the same combo, but no CELs/problems.

I told him to get his car on the dyno and have the A/F read (or hook up some sort of ODB2 reader and do it that way) - any other suggestions/knowledge to share?

 

from what i understand no matter what without kpro u cant get rid of the problem unless u trick the ecu with a o2 sim or there is another way some guys are using on clubrsx they are using spark plug non foulers on the second O2

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JdMB16Ahatch &raquo;</TD></TR><TR><TD CLASS="quote">from what i understand no matter what without kpro u cant get rid of the problem unless u trick the ecu with a o2 sim or there is another way some guys are using on clubrsx they are using spark plug non foulers on the second O2 </TD></TR></TABLE>

That's correct, but we have the secondary 02 sensor licked. This is the primary (wideband) O2 sensor...

 

does the casper sim only take care of 1 o2 sensor or both?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Halo &raquo;</TD></TR><TR><TD CLASS="quote">does the casper sim only take care of 1 o2 sensor or both?</TD></TR></TABLE>

Only takes care of the secondary (which really does nothing but make sure your catalytic converter is "working"). You really want the primary O2 sensor working correctly, as that helps your ECU adjust its' settings (someone correct me if I'm off base here).

 

Make sure you didn't accidentally plug the Casper's into the front o2.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by lube &raquo;</TD></TR><TR><TD CLASS="quote">Make sure you didn't accidentally plug the Casper's into the front o2.</TD></TR></TABLE>

It's not, he had that setup for a month or two before the light came on (this was only in the past week or so). It was fine prior to that.
And I have the same setup on my car and no problems.

 

check out what this guy did...

http://www.ephatch.com/forum/s...49779

 

he said its his primary messing up not the secondary

 

Thanks for your suggestion, but that's the secondary O2 sensor. As in number two. As in not number one, but two. As in two doesn't really do anything, but the primary one does (it's a wideband sensor and your ECU needs its' readings).

The guy is still having the problem (I told him he needs to either run it on the dyno and get the A/F read, or do the same with a scan/log tool). Anyone have any ideas? Anyone else's primary sensor just go bad after a while?

 

One last bump...

My buddy called up his Honda dealer and they just told him to "bring it in, leave it and we'll replace the primary O2 sensor" - they seem to be very, very mod friendly. I'd still like to know if his car is running lean or not, though. No one here has Hondata, a race header and some sort of A/F guage?

 

Well, my friend ended up taking his Si to Honda, they replaced the primary O2 sensor (even though he had race header, intake and a ton more mods) for free, under warranty. So much for the "it'll ruin your warranty!" comments, lol.

As for me, I dyno'd my car Sat. Pulled 159hp/134tq, which is about what I expected. I was running a tad lean from 4.5k-6.8k rpm (maybe 0.5 off), the guy at the dyno suggested I up the fuel a bit but that it wasn't a major problem. So I think my friends O2 sensor just bit the dust (he may have fouled it when he was removing his stock cat and putting on the race header).