I just installed a mugen header a week ago. Drove the car around for a week no problems then last night the check engine light decided to come on. So I pulled the clock/radio fuse and the light goes off. Fine. Well this morning I go driving around and the check engine came on once the car got to operating temperature. I pulled into a gas station to find the code. So I turn off the car turn the ignition to on and the Ckeck engine light blink once.

The problem: The fuking Primary HeateD Oxygen Sensor.
The solution: Well I reset the ECU again and once again the check engine light went off. So now I'm going to wait until the engine cools down then drive it and see if it comes on. If it doesn't great, but if it does. Here's the ******* flow chart.
1.) Is there a constant voltage?
2.) Check the fuel pressure.
3.) Check for a short in the wire.
4.) HO2S deteroiration.

All I can do is reset the ECU, check for exhaust leaks (shouldn't be any because if there were the light would have come on after installation), Check Primary O2 senor wire for falty connections, and I didn't abuse the O2 sensor when I was transfering it to the mugen.

BTW did I pull the code correctly. I didn't do it the way Toranto Prelude Club instructs us to but isn't just turning the ignition on and watching the blinks good enough?

 

I believe to pull the code properly, you have to jump the ECU first...ie, use a paper clip or small piece of wire..

I've never done this, however, last time my car had a light I remember reading this is the proper way to do it.

I believe you should be getting more than one blink...

Anyone else verify or clarify this?

 

There is a code of 1, which would be one blink right?? And code one is what I have listed above. I have the shop manual and the list of codes matched what Toranto Prelude Club put up. Antd they have code 1 listed also.

 

No, you didn't do it right. You have to jump the service conenctor with a jumper wire or a paper clip for it to display the code.

 

it will only blink once if its not jumped
you have to go to autozone and let them pull it for free
or get out the plug and put a paper clip or wire in it. then it will flash accordingly

even if you did have code one

it would flash one time real short.. then wait and then do it again. it dont just flash once and thats it.. it repeats the code over and over

 

no you didn't do it correctly. you gotta do it the way toronto prelude instructs you to.

Introduction -
When the computer (ECU) in your car detects a problem with how the car is running it reports it by lighting up the yellow engine light on your dash. Any Joe Schmoe can actually check what the ECU is complaining about as long as they know how.


Service Connector -
In order to get the code you'll need to find the service connector. On the 5th Gens it's on the right hand side of the centre console underneath a carpeted panel that just pops right out. The connector looks like a telephone connector and is plugged into a blue plastic piece that just serves as a holder. Unplug it and you'll see that it has two sockets in it that lead to two wires





Getting the Code -
You'll need a small piece of wire for this. Make sure the car is off. Just connect the two ports in the service connector together with the wire. After you've shorted the service connector, turn the key in the ignition to the on position (you don't actually need to start the car) and the yellow engine light will flash at you. There will be a series of long flashes, short flashes, and then it will repeat itself. Count the number of long flashes and short flashes and this will give you the MIL code. 2 long flashes and 3 short flashes is code 23. Once you've found the code, turn the key back to off and remove the wire from the service connector. You can look up the code in the following table.

click here http://www.hondaprelude.to/main_checkengine.html for full details. ( RY8127, your just lazy...jump the wires )

 

 

UPDATE: My car is weird.
Ok pulling the code seems easy enough, BUT like a said I reset the ECU and I just went for a long enough drive to get he car up to temp and for all system to be operating normally and NO CHECK ENGINE LIGHT. So I'll really let the car cool down tonight and drive it around tomorrow morning as that's what I did last time when the check engine light came on.

Thanks for the input.

 

Ry,
Thats what you get for spending $900 on a damn header just playin.

It must be a sporatic(sp?) issue..something that it only catches on occasion.

Did you get the code yet?? or was it actually 1?

 

haha maybe his o2 sensor ain't used to the air flow coming from the new mugen header. i changed the air filter on my beater once and the cel came on for 2 days and disappeared. cars have feelings too.

 

No I didn't get a code yet because like I said the ******* goofy engine light didn't come on, so I'm going to carry and paper clip or wire in my car and when the goofy check engine light comes on I'll pull the code correctly.
Edit
Seems my prelude is being a lil bitch in the middle of her cycle.
Reeeeeeeeally.......... *sarcastic vioce* I didn't that a header would increase or improve air flow. Yeah maybe the increased air flow has beat to death that ******* O2 sensor.



[Modified by RY8127, 5:30 PM 3/8/2003]

 

check engine lights are really simple. they come on under certain conditions. yours being your o2 sensor. for the check engine light to come on your car needs to have a constant problem. if you talk to a honda tech you can learn more about this...
all dealers have a basic test drive. being, starting the car up and driving it a certain way... ie: 5 min @ 25 mph, then stop and go, then 25 min @ 75 mph... if your computer picks something is wrong it stores it inside the memory. when your car is shut off and then started again you can run it through the next test drive... if the computer picks the same problem up, it sets a code off.... follow me?
therefore, if your not driving it the same all the time... you might not be triping the code. it might take 2-3 before your computer picks up the code again.

just replace the sensor, chances are it was damaged or not installed correctly...

 

WOW very good that's exactly what I have.
Update: So tonight I drove about 75 miles, not 2 minutes into the trip the CHECK ENGINE LIGHT came on. Couldn't check it right away but I just checked it and the code (low and behold was, Drumroll please) is 61
-Now the description of code 61:
--Primary Heated oxygen Sensor *slow response*
--Probable Cause------>Primary HO2S deterioration.
- -->Exhaust system leak.
The flow chart (really simple)
-Problem varification-
do specific driving conditions (like the guy above mentioned)
-Is DTC PO133 (code 61) indicated?
-IF yes---->replace Primary O2 sensor.
-If no-----> Intermittent failure system is ok.

So MUGEN fried my primary O2 sensor. Damn Think I can call Mugen and they'll replace my O2 sensor. Or should I even put a new one in if there's a possible likelyhood that it might get fried again?

 

Have yopu ever tried running any kind of fuel system cleaner or octane boosters??
I hear some of those will **** up the o2 sensor just in one try.Also,leaded gas will do it too.

 

I highly doubt that the Mugen header fried your O2 sensor. I would more than likely place the blame upon the install. O2 sensors are very fragile and can't be beaten around. I hope you didn't leave it dangling under the car when you installed the header, if you did there's your problem right there. My Mugen header or exhaust hasn't killed any of my sensors.

 

Holy Crap! Someone with the EXACT... I mean EXACT... problem that I have. 2 weeks after my Mugen header install... check engine light. Slow responding primary O2 sensor. It only does it on occassion. Very annoying!

I've reset it about a half dozen times now. I'm giving up! I'm going to have the dealership replace it in the next couple of weeks when I do my 52,500 mile service.

Hopefully this problem will not come back. O2 sensors are freakin expensive!

Let's keep each other posted on this problem. I feel your pain, man! King Motorsports even installed mine.

 

I've never put leaded gas or octane booster in my car. When I was doing the install, I couldn't get a nut off from the 2 piece. So I had the nuts loose on the cat and the 2 piece and drove over to Midas and had them take off that bitch of a nut. Once they did that the A-pipe came off. The mechanic there took off the O2 sensor. THe mechanic was careful (he didn't take on off the A-pipe with sensor still on and let is dangle.) I then place it in my car and then installed when I got the Mugen on. Then I drove with open pipes back to my house to complete the install As far as I can remember I didn't abuse the O2 sensor between when it was taken off and when I put it back on.

 

HAHAHA See ya'll there is someone out there who has the same problem as me I'm not crazy or some stupid newbie.
Hey jji106 I was calling to e-mail King about my problem and see what they had to say about, have you talked to them about it?

 

Your problem is intermittent. Shortly after swapping my DC for my Kami, I was getting that code about once a week. Then it slowed to about once a month. Now I hardly get it at all. Throw CEL, clear code, go on with life. I figure I might have got it a little dirty during the install, and the dirt slowly burned off. I let it hang during the install, as Timeracer suggests can cause a problem, so perhaps it did. But I don't get the code anymore.

 

Yeah, I called Scott Zellner at King after the second time I had to reset the code. I even called him from the dealership as the guy was checking the code because the Honda Technician was trying give me a bunch of BS about aftermarket parts! I told the Tech he was full of **** and I had THE GUY on the phone that could prove it!

Scott told me that the O2 sensors on Preludes are pretty weak and that this just happens. I thought that maybe something had gotten on it and it would just burn off, but now I'm just tired of messing with it and I'm going to replace it. I am going to have it replaced on 3/17/03.

If you call King, let me know if they tell you the same thing. I'll try and keep you posted on my situation (as in, if the CEL comes back on even after I've replaced the primary O2 sensor)

So on St. Patrick's Day, I know I'll be crying in my green over the sh*tload of money that I just forked out for a stupid F*cking O2 sensor. I'll have a green for you too!

 

ummmmk, my brother has an extra he isn't using... it's the secondary but i believe it's identical to the primary. IM him (turbolude97)... and i might have an extra myself soon also

oh, forgot to mention. My CEL kept indicating secondary O2 reading too high or too low.. and I'd reset the ECU and in a few hundred miles it would be back on. I said "forget it" and drove quite some time with the CEL on... on day i started my car up and it turned its self off! so you could just use my method lol


[Modified by rjr162, 3:47 PM 3/10/2003]

 

o2 sensors are so easy to install. i hope you know you can self install???? plug and play man.... good luck with the $200 price from honda though. i just replaced mines for a 4th gen and thats what it cost me.... good luck.