emissions on 99 civic si NEED HELP
 

I'm having problems with emissions on my 99 civic si. I took it to advanced to get it scanned before taking it to get tested just to be sure. So when scanned it showed i have 2 codes, knock sensor and #1 oxygen sensor, but i don't have a engine light on so the guy told me they could have been stored in the ECUs memory, he erased them and told me to come back in two days. So i go back and the codes are still there, i go get the sensors replaced at my buddy's shop and re-scan after a few days and the codes are still there. My buddy tells me it might be the engine wire harness because it was hacked, we replace that and same thing.

Now, i've noticed that my check engine light turns on when i turn the key to the fisrt click on the ignition but it doesn't turn off after a few seconds like in other civics!
It shuts off only after i turn the car on and sometimes the light will blink right after the car is on.

Could it be the ECU??? It is the original P2T ecu which i opened and looks good from the inside

Please help

Re: emissions on 99 civic si NEED HELP
 

Could be a bad ECU, but first test the wires.

Re: emissions on 99 civic si NEED HELP
 

Which wires?

I replaced the engine wire harness with a used one but i checked it and it looks good.

Re: emissions on 99 civic si NEED HELP
 

You check wires with a multimeter not visually.

Also, are both sensors properly pinned to the ECU?

Re: emissions on 99 civic si NEED HELP
 

Gotcha will do that, thanks!

Will make sure they are properly pinned, i didn't think of that since everything is stock.

Re: emissions on 99 civic si NEED HELP
 

Ron

I checked everything and the connector to the knock sensor was bad, fixed it, tested it and its good. Every other cable was tested and is pinned correctly.
I reset the ECU by removing the fuse for 1 minute, turned the car on and same thing happens with the cel light as before. I turn the key to II and cel light turns on and stays on, it never turns off. I start the car on and cel light turns off after two seconds.
I also tried to check for cels manually and i couldn't do it, i jump the brown and black wire clip by the ECU turn the key to II, cel light just stays on!

Everything points to the ECU but i'm having trouble finding one locally. Is there something else to check and find out why is the cel light stays on in II?

Re: emissions on 99 civic si NEED HELP
 

It does sound like an ECU problem.

When you turn the key to ON(II), the CEL stays on steady, but does the fuel pump prime?

Re: emissions on 99 civic si NEED HELP
 

Correct on (II) cel light is on and steady, i hear the fuel pump priming. When the fuel pump is done priming, i hear the ECU make a "click" sound. That's when the cel light should turn off, correct?

Re: emissions on 99 civic si NEED HELP
 

I tried to check for cels to see if the codes were still there following the instructions on THE NEW CEL THREAD (how to & codes) but the cel light just stays on and steady

Re: emissions on 99 civic si NEED HELP
 

Yep, the CEL should turn off when the fuel pump does. Do you know anyone that would let you swap their Civic ECU into your car?

Re: emissions on 99 civic si NEED HELP
 

That's called CEL code 0, which indicates a problem with the ECU power/ground circuit or the ECU itself.

Re: emissions on 99 civic si NEED HELP
 

That's what I'm trying to do but looks like i'll end up buying an ECU. I'm afraid of buying a used one, can't trust people anymore might end up buying something worst than mine.

We'll see what happens Thanks Ron greatly appreciated!

Re: emissions on 99 civic si NEED HELP
 

Ron

So i finally got a hold of a ECU, its currently being used in another SI and it works like it should. But when in my car it does the same crap!!

Any more ideas???

thanks!

Re: emissions on 99 civic si NEED HELP
 

Also out of curiosity i checked the under dash fuse panel and it looks like something bad happened before. There are two empty spots where the plastic surrounding melted a bit, just thought i'd mention this.

I don't have a fuse cover to see what those spots are for but i'm looking for my owners manuals right now.

Re: emissions on 99 civic si NEED HELP
 

Post a picture.

Here's the diagram:


http://i639.photobucket.com/albums/u...cture_3573.jpg

Re: emissions on 99 civic si NEED HELP
 

UMMMM if the car is Stock and a 99 you have to have a OBDII ecu and Will need a OBDII scanner to read the codes.
sounds like your running the OBDI code reading procedure.

my 2000 honda Van the Cel Stays on till i start the car then goes out and i have NO cels stored in ECM.

Also if it is OBDII then the only way to clear the codes from Memmory is to use a Code scanner.

Re: emissions on 99 civic si NEED HELP
 

For 92-00 Civics, codes can be pulled either with a code reader or by jumping the service connector, and the ECU can be reset either with a code reader or by removal of the 7.5A hood Back Up fuse for a few minutes.

Re: emissions on 99 civic si NEED HELP
 

here's a pic of the fuse panel.

Re: emissions on 99 civic si NEED HELP
 

The dash fuse box does look damaged by a short. Is there additional damage on the rear side? You might be able to see this with a mirror. Nonetheless, it may be wise to replace the fuse box. Are you having any other electrical problems besides the CEL codes and CEL?

Re: emissions on 99 civic si NEED HELP
 

I found the owners manual, i don't have a SRS fuse and some others are the wrong rating or whatever.

No other problems just one weird thing it does, is that when i turn on the ignition fast it will not crank and i will hear like a shorting sound. Then i try again slower and it cranks with no problem.

I will go check the back of it right now....

Re: emissions on 99 civic si NEED HELP
 

There's no damage on the rear of the fuse panel.

Last time I only checked that connectors b an c to the ECU were properly pinned. Just now I checked connector A and it doesn't match to the obd2b schematics found on efsquad...here's what I have

1 empty. 2 brown. 3 empty. 4 black with white. 5 empty. 6 red with yellow. 7 empy. 8 pale green with white. 9 blue. 10-11 empty. 12 light blue w white. 13 white w red. 14 empty. 15 blue w yellow. 16 green. 17 blue. 18 green w orange. 19 black with red. 20 green w yellow. 21-24 empty. 25 green w white. 26 empty. 27 green w red. 28 pale green. 29 empty. 30 blue w red. 31 green. 32 empty.

Re: emissions on 99 civic si NEED HELP
 

The Brn wire at A2 belongs at A10. This miss-pinned wire is for the service connector and explains the odd behavior of the CEL. Properly rewire connector A.

http://i639.photobucket.com/albums/u...cture_5121.jpg

Re: emissions on 99 civic si NEED HELP
 

And the rest are pinned correctly?

Re: emissions on 99 civic si NEED HELP
 

No. Compare the diagram and your list. Most wires appear to be miss pinned.

Re: emissions on 99 civic si NEED HELP
 

Alright i will follow the diagram, again thank you so much!!!

Hope this works