Fox T-Bird/Cougar Forums

Technical => Engine Tech => Topic started by: ThunderFox on April 12, 2014, 12:01:13 AM

Title: KOER Code 42 Opinions
Post by: ThunderFox on April 12, 2014, 12:01:13 AM
Hi guys, I just picked up an '86 T-Bird with the 5.0. The car runs great except for the service light being on for about the first 10 minutes of driving. After that it goes away, but if I shut the car and start it right back up, the light is back. If I don't drive the car for a few days it even has a little bit of a miss/stumble within those first 10 minutes. I did a full ignition tune up when I got it, so I know it's not that.

I see different descriptions of the code, some say it's an O2 sensor problem but others indicate a rich condition. What do you guys think and what would be the be the best way to attack this?

Thanks! Been searching around the forums gaining some info. Not totally new to the game, I had a 1990 Mark VII SE a few years ago.
Title: KOER Code 42 Opinions
Post by: MY83T on April 12, 2014, 01:22:30 AM
Quote from: ThunderFox;432192
Hi guys, I just picked up an '86 T-Bird with the 5.0. The car runs great except for the service light being on for about the first 10 minutes of driving. After that it goes away, but if I shut the car and start it right back up, the light is back. If I don't drive the car for a few days it even has a little bit of a miss/stumble within those first 10 minutes. I did a full ignition tune up when I got it, so I know it's not that.

I see different descriptions of the code, some say it's an O2 sensor problem but others indicate a rich condition. What do you guys think and what would be the be the best way to attack this?

Thanks! Been searching around the forums gaining some info. Not totally new to the game, I had a 1990 Mark VII SE a few years ago.

I have the exact same condition/issue on my 87 5.0 Cougar XR-7......i am interested in this as well......  Welcome to the forum, where in NY are you?
Title: KOER Code 42 Opinions
Post by: V8Demon on April 12, 2014, 02:42:10 AM
You got any codes showing up KOEO?

Time for both of you to break out the multimeter  ;)

Here:

(http://351winsor.com/joel/EEC-IV/O2_Sensor_Testing.gif)
Title: KOER Code 42 Opinions
Post by: ThunderFox on April 12, 2014, 03:21:31 AM
Quote from: MY83T;432195
I have the exact same condition/issue on my 87 5.0 Cougar XR-7......i am interested in this as well......  Welcome to the forum, where in NY are you?

Thats strange, at least its not some off the wall issue. Im in Westchester.

Quote
You got any codes showing up KOEO?

No codes for KOEO.
Thanks for the info on the O2 test. I will give that a try. I actually picked up a couple of O2's on closeout from Rockauto for $8 each just in case thats the problem, but I'm wondering if maybe theres a leaking injector or something. We shall see...
Title: KOER Code 42 Opinions
Post by: Haystack on April 12, 2014, 03:24:42 AM
http://sbftech.com/index.php?topic=29771.0;wap2

pull out your volt meter.... or....

be lazy and swap wires for the o2 sensor and see if the codes switches sides. if it does, o2 is junk and you can just replace it. its a bit of a bear to get to, but you should be able to do it in about an hour.

i don't recommend running it any longer then it takes to get codes this way, although, the o2 code essentially disables them then runs off of a pre set table instead.

my 86 had the same code. no check engine light or driving problems. failed emissions so i swaped it out once i ran codes and found it as bad.
Title: KOER Code 42 Opinions
Post by: ThunderFox on April 14, 2014, 11:57:44 AM
I didn't get a chance to take a look at this over the weekend. Does anyone have a diagram or description of where the O2's are on my car? The Haynes manual(mostly horrible) does not even list them. Are they right after the exhaust manifold on each side?

Thanks!
Title: KOER Code 42 Opinions
Post by: Haystack on April 14, 2014, 12:23:22 PM
Yes, right on the end of the exhaust manifold on each side. smog  gets in the way passenger side. the plug is four wires right up behind the intake manifold near the pcv valve.
Title: KOER Code 42 Opinions
Post by: ThunderFox on April 14, 2014, 12:32:46 PM
Awesome. Thank you! Hopefully I can get this done this week so I can focus on body work.
Title: KOER Code 42 Opinions
Post by: ThunderFox on April 18, 2014, 06:57:12 PM
Quote from: Haystack;432330
Yes, right on the end of the exhaust manifold on each side. smog  gets in the way passenger side. the plug is four wires right up behind the intake manifold near the pcv valve.


Ok, got a chance to look at it today...how do you get to the passenger side one? It looks impossible from the bottom and from the top there is stuff in the way. Any specific tips or instructions to get it from the top?

Thanks!
Title: KOER Code 42 Opinions
Post by: Haystack on April 18, 2014, 07:08:14 PM
Take the smog rubber hoses out, and bend the one bracket out of the way or cut it off. Its all just hose clamps, not hard but time consuming. rent the tool, and if you don't have any wobbly or swivel extensions, pick some up for $10-15 at harbor freight. they work like u-joints but stay rigid so they are easier to use in tight spots.

i cut the connector off of my old sensor, made fixing the ed.cross thread a million times easier

before you cut yours off, make sure you have the right connector. It took me 3 tries to get.the correct one.
Title: KOER Code 42 Opinions
Post by: ThunderFox on April 18, 2014, 07:13:11 PM
Cool, so I can remove all of the hoses in the way by just disconnecting them. What is that bracket with the hole in it for exactly? Am I missing anything if I unbolt it and toss it. Doesn't seem to serve any true purpose...
Title: KOER Code 42 Opinions
Post by: Haystack on April 18, 2014, 07:24:17 PM
When i twisted mine it broke right off. I'm not worried about it.

its still a pain to get to. the wobblies really, really help.