Since I don't want to have to rewrite this whole speel from what I have posted in a different thread, I will c/p it.

Forewarning, do not reply with any "just take your headers off" or "shoulda kept it stock" posts, I'm not looking for that, I came here for help. Thanks.

This summarizes my whole deal with my local Honda service center, and the six times I have gone there, concluding with my car nearly breaking down.

So, about a month and a half ago, my CEL comes on, a few people know this because they helped me address the problem, my gearing slipped a little bit during higher RPM's, so I went into the shop, they hooked it up to the machine, it was code p0145 or something like that, bad secondary o2 sensor. Ok, so they couldn't jack it up because I have side skirts and a front bumper and they were to afraid, this being after my second time going there, and leaving it ther for full days both times (8-3). So, I said screw it, give me the part, I'll go to my mechanic and he'll do it (he's a trained honda-tech). So, he does it, but the CEL comes back on the next day. Great, so I take it back to Honda, leave it for the whole day AGAIN, I show up at 3, and then he decides to hook it up the machine for the code (I guess he couldn't do it during the 7 hours I had left it there), running too lean. So, I said whats the problem, he shrugs.
So I'm going great, now they have no f*** idea what the problem is. So I called up my mechanic, asked him if he noticed anything when doing the o2 sensor install, he said with the aftermarket headers that the harness for the o2 sensor didn't fit correctly. So I leave my car there for the 4th day and he hooked it up and it said running too rich, and he connected the wire. So I walk out, run my car for 2 days, everything is capische, then the CEL comes on again. I take it in again, I said figure out this problem, get a new harness or what. So, I come back at the end of the day, do a walkaround on my car, and the aftermarket front bumper has huge scrapes on the front and deep scrapes on the front left side of it, after I had told them how to jack it up on the lift, they had still scratched it all up. In his defense, he offered to get it all painted, but I said screw it, I'm probably taking the front off, no need (which I did end up doing). During my fifth visit one of the mechanics tried convincing me that chipping my car (because he was convinced it was and that I was lying to him) and all this baloney, I flat out told him he was stupid.

In any case, I found out that there is an extension for the harness with the DC Headers, but from the guy who did it, the trained Honda-tech mentioned in my post, said that it shouldn't cause problems.

Well, I woke up this morning to go to work and when I started driving down the street, my car was accelerating at a jumpy pace, knocking like hell and all sorts, I immediately turned around and drove back home. Last night when I put my car in park and left it idling for a few seconds, it started knocking like hell and cut out. So, there is obviously a problem with it getting so lean that its starving the engine. I called up my friendly Honda service manager, who I had seen before all those times. He was convinced that it was the harness causing all these problems, and stated his unweighty response of "bring it in and we'll work on it" Now after hearing this 091823409124 times, I have reason not to believe him. If my car goes anywhere, its going to be by tow truck. Now, I was going to bring it into my mechanic who could fix it theoretically, but I'm going out of town and he can't keep it in his garage for that period of time.

Thank you in advance for any help.

 

Hmm how does this extension connect? I'm not familiar with those yet.
also are all of the o2's Honda brand with uncut (or soldered) wires?

 

I think that the headers made the difference where it hanged by like a mm or two and so it wouldn't fit right, so with the headers came a wire extension.

When you say o2's you mean the sensors? The sensor I replaced came from the Honda parts desk at the service center.

The harness should still be Honda, but I'm not familiar with what it would be with an "extension" since I didn't DIY.

 

What i'm getting to is the connections. Honda doesn't make an extension harness because it isn't needed.
What you need to find out is if the extension harness uses the stock connectors or if the wires are spliced. If the wires are spliced you need to make sure they are int he correct positions and that they are soldered and shrink wrapped. Butt connectors will not work in this circumstance.

 

ok, just the thing I needed to hear, I will look into that ASAP, thanks for the help.

Could/would this cause all of the above?