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Topic: KOER Code 42 Opinions (Read 1831 times) previous topic - next topic

KOER Code 42 Opinions

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.
1986 Thunderbird 5.0
-FRPP Wires and upgraded ignition parts.
-H.O. Upper Plenum / EGR Spacer / TB

KOER Code 42 Opinions

Reply #1 –
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?








1983 FORD THUNDERBIRD HERITAGE 5.0
2008 SAAB 9-7X AERO 6.0 (LS2) 1 0f 554 Made
2011 FORD FLEX SEL Family Hauler

KOER Code 42 Opinions

Reply #2 –
You got any codes showing up KOEO?

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

Here:

-- 05 Mustang GT-Whipplecharged !!
--87 5.0 Trick Flow Heads & Intake - Custom Cam - Many other goodies...3100Lbs...Low12's!

KOER Code 42 Opinions

Reply #3 –
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...
1986 Thunderbird 5.0
-FRPP Wires and upgraded ignition parts.
-H.O. Upper Plenum / EGR Spacer / TB

KOER Code 42 Opinions

Reply #4 –
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.
Quote from: jcassity
I honestly dont think you could exceed the cost of a new car buy installing new *stock* parts everywhere in your coug our tbird. Its just plain impossible. You could revamp the entire drivetrain/engine/suspenstion and still come out ahead.
Hooligans! 
1988 Crown Vic wagon. 120K California car. Wifes grocery getter. (junked)
1987 Ford Thunderbird LX. 5.0. s.o., sn-95 t-5 and an f-150 clutch. Driven daily and going strong.
1986 cougar.
lilsammywasapunkrocker@yahoo.com

KOER Code 42 Opinions

Reply #5 –
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!
1986 Thunderbird 5.0
-FRPP Wires and upgraded ignition parts.
-H.O. Upper Plenum / EGR Spacer / TB

KOER Code 42 Opinions

Reply #6 –
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.
Quote from: jcassity
I honestly dont think you could exceed the cost of a new car buy installing new *stock* parts everywhere in your coug our tbird. Its just plain impossible. You could revamp the entire drivetrain/engine/suspenstion and still come out ahead.
Hooligans! 
1988 Crown Vic wagon. 120K California car. Wifes grocery getter. (junked)
1987 Ford Thunderbird LX. 5.0. s.o., sn-95 t-5 and an f-150 clutch. Driven daily and going strong.
1986 cougar.
lilsammywasapunkrocker@yahoo.com

KOER Code 42 Opinions

Reply #7 –
Awesome. Thank you! Hopefully I can get this done this week so I can focus on body work.
1986 Thunderbird 5.0
-FRPP Wires and upgraded ignition parts.
-H.O. Upper Plenum / EGR Spacer / TB

KOER Code 42 Opinions

Reply #8 –
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!
1986 Thunderbird 5.0
-FRPP Wires and upgraded ignition parts.
-H.O. Upper Plenum / EGR Spacer / TB

KOER Code 42 Opinions

Reply #9 –
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.
Quote from: jcassity
I honestly dont think you could exceed the cost of a new car buy installing new *stock* parts everywhere in your coug our tbird. Its just plain impossible. You could revamp the entire drivetrain/engine/suspenstion and still come out ahead.
Hooligans! 
1988 Crown Vic wagon. 120K California car. Wifes grocery getter. (junked)
1987 Ford Thunderbird LX. 5.0. s.o., sn-95 t-5 and an f-150 clutch. Driven daily and going strong.
1986 cougar.
lilsammywasapunkrocker@yahoo.com

KOER Code 42 Opinions

Reply #10 –
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...
1986 Thunderbird 5.0
-FRPP Wires and upgraded ignition parts.
-H.O. Upper Plenum / EGR Spacer / TB

KOER Code 42 Opinions

Reply #11 –
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.
Quote from: jcassity
I honestly dont think you could exceed the cost of a new car buy installing new *stock* parts everywhere in your coug our tbird. Its just plain impossible. You could revamp the entire drivetrain/engine/suspenstion and still come out ahead.
Hooligans! 
1988 Crown Vic wagon. 120K California car. Wifes grocery getter. (junked)
1987 Ford Thunderbird LX. 5.0. s.o., sn-95 t-5 and an f-150 clutch. Driven daily and going strong.
1986 cougar.
lilsammywasapunkrocker@yahoo.com