i finally finished my header installation.. now my check engine light decides that it wants to be seen... after about 10 or 15 minutes of driving the light will come on. the only thing that i could think of would be the fact that i left the rubber hoses for the air unplugged, and maybe that is giving the o2 sensor a funny reading. can i plug these lines? does anyone else have any ideas?

thanks,

david

 

Try to check to see if you are getting into closed loop, you may need a heated o2 sensor, some headers don't allow it to get hot enough fast enough and that may throw a code. Check to see what code you are getting first, that would help the most right now.
You should be able to plug the hoses no problem.

 

ok now call me stupid but how do i check to see what code im throwing? i suck when it comes to anything to do with a computer...

thanks,

david

 

Its easy. here is a link so I don't have to write all this down, I'm lazy! Read the link and then refer back to this to further simplify it.
https://www.thirdgen.org/faq/thirdgen.shtml#misc
For your car you would use pins 5 & 6 on the DLC as shown, or the top two on the right.
The check engine light flashes in the key on position. Each code is two numbers. It flashes fast for the first number, has a break, and then flashes fast for the sencond number. So two quick flashes is a 2, then a noticable break, then four more quick flashes is a 4, this is code 24 for example. It will flash each code three times. if there is more than one trouble code there will be a long break (maybe 2 seconds) inbetween each two number code.
You should always get a code 12 first, this says the DLC is working correctly. after the code 12 you will have the long break and then the first trouble code.
So you will see codes 12, 12, 12,____ trouble code, trouble code, trouble code,____, and if there is only one trouble code it goes back to 12, 12 ,12,____ and then the trouble code again. It will do this until you turn the key off or remove the paperclip. If you have more than one code it will flash them all before doing 12 again, and then flashes them all again and so on.
I really hope this makes it as easy as possible.

 

Oh yeah, the DLC port should be located up under the dash on the driver's side. take off the fuse panel cover and look for a black rectangular connector looking thing with 12 pins. If you can't find it take that whole cover off to find it, but it should be near the fuse panel for easy getting to.

 

i checked the codes and it gave me a 13 which means "13. Oxygen sensor signal stays lean during warm engine cruise" so how would i go about fixing this?

thanks,

David

 

Wow. I just went back and read some of those Q&A sections. It looks like it's time to update some of them. For example:

Q: Should I use self-aligning or non-self-aligning rockers?

A: You have to use a self-aligning type otherwise you will have to pull the heads to tap them since the studs are pressed in.

I think we all know better than that.

As for the code retrieval section, the ALDL pins are misidentified in the diagram, and the code cross reference is incomplete.

Try this instead:

You'll need to make a jumper from a short (2") piece of bare wire or a paper clip. Form the paper clip into a "U" shape. You'll also need a note pad, pen or pencil, and the ignition key.

With the engine and ignition turned off, locate the ALDL connector under the dash, just to the right of the steering wheel in the driver's foot well area on Firebirds, and on the left on Camaros. There should be a small rectangular cover over the access hole in the lower dash trim.



Insert a tool as described above (paper clip) into the 'A' and 'B' terminals on the ALDL connector:



WITHOUT STARTING the engine, turn the ignition to the "RUN" position. Watch the Malfunction Indicator Lamp (MIL) - it will begin to flash. This is also commonly called the "Service Engine Soon" or "SES" lamp. The first code will flash three times, and will usually be a code '12'. This is encoded by one flash of the lamp, a brief pause, then two successive flashes of the lamp. Each code will repeat three times, so you should see a "Code 12" flash three times. Any other error codes will follow in numerical order, and each code should flash three times. After all codes have been displayed three times, the "Code 12" will again flash three times, then all other codes will follow as described earlier. This cycle will continue until the jumper is removed or the ignition is turned off.

After you have made a note of all error codes, turn off the ignition and remove the jumper immediately. If you forget to remove the jumper and attempt to start the engine with it in place, you could damage the ECM. For this reason you should remove it immediately.

Once you have a note of all error codes, check this file for the decoding:

GM Error Codes.pdf.

You'll need Adobe Acrobat Reader to open/print the file.

 

Since you JUST finished installing headers, why not double-check to make sure the O2 sensor is plugged in? Make sure the wire didn't get burned, or maybe the connector came undone.....





HTH

 

my bet is you need a heated sensor. one wire gets ignition-switched power, one is ground and the third sends the signal to the ecm

 

If it was the O2 sensor, odds are the light would ocme on at startup.

Sounds to me like the CTS is unplugged. Without even reading the codes, you can often identify that by this behavior: You get in the car, drive off, 10 minutes or so it comes on; as you drive down the road, you flick the key off and back on, it goes out; comes back on about 10 minutes later.... etc. ad eternam.

Disconnected CTS wire = about -72° or some such to the ECM; it's smart enough to know that the engine temp should increase above that within a few minutes of running, so if it doesn't, it knows something is wrong.

 

i checked the codes and it gave me a 13 but i can turn the key off and back on and it will take a little while before it comes back on.

david

 

Like said above, just recheck to make sure the o2 is indeed pluged in. And about the CTS (coolant temp sensor) go around the heads and make sure all the connectors got plugged back in. there is one on the driver's side in front right behind the first primary, it has a clip on connector. There is another on the passenger side back by sparkplug 6 under the header that I had trouble with.
Either something is unplugged, or you might need a heated o2.

 

Seems to me 13 = CTS but I could be wrong

Sensor between #1 & #3 plugs = gauge sending unit

Sensor between #6 & #8 = fan switch

The one you want to look at is in the thermostat housing

 

what do i need to look at in the thermostat housing? all of the wires were plugged in, but i will recheck to make sure that they have a good connection.


thanks,

david

 

The CTS could be bad and reading incorrectly, but the only way to tell is to hook up a scan tool to your computer or maybe read the resistance of the sensor while running(never done this). I would think that it being unplugged would cause a rich condition, not a lean one.

If the oxygen sensor has over 60k miles on it, it may need replacing. A new cts wouldn't hurt either. At least then you know the sensors are good. Burning oil can cause your sensor to malfunction and give a code 13 as well. The cts is in the front of the intake below the thermostat housing.

 

when i installed my headers. i forgot to plug the O2 back in. and the check engine light didn't come on until it got into closed loop..

 

Hmm i had problems to and i still have after installing hedders. I just removed the emission stuff and didnt plug it. I dont think you have to. My car says egr trouble when i start it if its cold outside. If the sun has been shining or if the engine still is hot when i start her up, the dam light doesnt come on and everything is ok. I think this is really strange. Anybody has a solution to this problem? It seems to be temperature depending.