I just got a p28 ecu for my civic (finally). Just starting up, the idle bounces, but after a short drive it calms down. However, the big concern is the CEL that comes on right away after startup.
I checked the code, and it's throwing a code 2 (blink-pause-blink-pauuuuuuuuuuuuuuuuuuuuse-blink-pause-blink-pauuuuuuuuuuuuuuuuuuuuse...)I know a bunch of the CEL guides say there is no such thing, but some of them say that it's a code for a secondary bank O2 sensor. As far as I know, my car only has 1 o2 sensor.
Is there any way to disable this, or make the ECU think that it should only have 1 o2 sensor, or that the hypothetical 2nd o2 sensor is ok?
Thanks!

 

The P28 only looks for ONE O2 sensor.

 

Ok. If it's relevant, with my P06 ecu, there aren't any CEL codes. Also, my purge control solenoid valve is missing- either I can't find it, or it's not there, either way the vacuum line and electrical connector are just hanging, would that have anything to do with it?

 

Ok, so after watching some videos of what a long and short flash look like, It's not a code 2, it's a code 20. Looking at the flowchart, is this a bad ecu? Is there something that my car and the ecu aren't 'agreeing' on?

 

Probably because the P06 isn't looking for VTEC components. What engine is in the car and why are we running a P28?

 

1st find out the actual code and correct the problem
If it still idles bad then it could be a number of things:
-coolant needs bleeding
-vacuum leak
-iacv needs cleaning
Among others..search the 100s of threads dealing with idle issues,good luck

 

Like my sig says, it's a 95 dx with a mini me swap in (z6 head with a b7 block)
I'll go recheck the code *runs outside*

 

Sorry. But I can't assume the car in your sig is the same car. Some people own more than one car.

Also check the FITV. That wouldn't throw CEL but it is also the cause of surging idles.

 

No problem. Ok- so I was mistaken (again). I guess that I didn't notice the short blinks earlier, but it's coding 21 & 21 (vtec stuff).
I guess I've been had. The guy that did the swap assured me that the vtec stuff was all wired in correctly and would work perfectly.
The vtec feels and sounds like it's kicking alright on acceleration... gremlins, gremlins, gremlins

 

Yup. That's why the P06 has no issues.
Now you have to fix this.
Code 21 VTEC spool solenoid valve
http://www.google.com/search?hl=en&s...x+code+21+vtec

 

So where are the vtec spool solenoid valve and vtec pressure valve? Or rather, where SHOULD they be?

 

Check Google for images.

 

http://t2.gstatic.com/images?q=tbn:A...hcd3ejV_C-7xe8

These, right?

 

Ok, so I took off the Vtec bits, cleaned off the connectors, disassembled the vtec valves from each-other, cleaned them up (did the same thing to the fitv and iacv and tried to get the air bubbles out of the coolant lines for good measure). I also reset the ecu (pulled the backup fuse while I was doing the work).
The good news: the idle is a little more steady. It doesn't do the big oscillations that it used to (unless I mess with anything on the tb, like the idle adjustment screw).
The bad news: I'm still getting the CEL with codes 21+22. I'm going to have to hit the books and follow the flowchart in the service manual. If anyone knows any little tips or tricks, it would be MUCH appreciated.

 

So I think I found the problem! I was looking at the harness at the ECU- I do not have a wire coming out of A4 or D6! The engine compartment harness is wired for vtec, but the ecu side is not! I guess I hadn't been hitting vtec- it was just wishful thinking on my brain's part...
Now the question: do I try and tackle it myself, or pay someone to do it for me?
__________________

 

Ok, so i wired up my ecu to vtec stuff! YAY! CEL codes 21 and 22 gone! Haven't taken it out for a spin, but I'm happy about that.
The idle issue, however, is still bugging me. I cleaned the IACV, FITV, sprayed looking for vacuum leaks, etc... when the idle did calm down I knocked on the IACV with my screwdriver and it made the idle act up again. I unplugged it (for now) and that instantly calmed the idle down, but it's sitting at ~1300 rpm. Way too high, right? I put in my paperclip and tried to adjust the idle screw, but it was screwed all the way in, and any adjustment made the idle jump up.
What is the reading across the iacv electrical terminals that I should be getting?
Can I run my car with the iacv unplugged for now?