HUGE problem with CEL, need help here

[Slow5.0]

CEL flashing when I start my Stang , need help

Well here is deal
Tonight after work I start my car for 5 min before driving ,and for no reason check engine light blink once and it was gone like it come,I look at autometar A/F ratio gauge (I have switch on/off/on so I can read right and left side O2 Sensors) and I find out that right O2 doesn't work or it read too reach
So I turn off car, get paper clip and plug in place where is CE testing,than I start with testing
Looks like I have EGR code but thats because I have plugged EGR long time ago, than I have Collant sensor out off range and right O2 runing too reach, so I clear codes
BUT when I turn key on I heard PCM going to test CE again, i'm like WTF, there is no paper clip in conecctor but still,and that run test about a few second than it stop like everything is fine
I drove car to my home ,everything seems fine except right O2 sensor read too reach or it is dead
Tomorrow I will get my laptop and see on Tweecer do I have signal from right O2
I just wandering did anybody else have this kinda problem before

 

[Slow5.0]

C'mon guys this thing drive me nuts
Let me try explain again almost everytime when I turn key on /engine not runing and almost every time when I start Stang it start flashing codes like i pulg CE tester
But after like 5-10 or so it stops like it come
I have no codes ,BUT what the hell is wrong,
All I know it read rich non-stop on right O2 sensor (I have A/R ratio gauge and before never read rich all the time so don't say those gauges don't works)
I try put spare O2 but same thing, I try put spare CCRM (fuel pump reley) same thing, i pulled TwEECer from J3 port on PCm but nothing,than I tryed with spare ECT but nothing, I have restart battery but no helps,
Tomorrow I have one more thing to try put spare PCM

Did anybody have similar problem

 

[BlackVert]

the sensors work by comparing outside o2 to o2 in the exhaust.

the outside o2 comes in thru tiny leaks in the connector.

maybe the connector got some stuff on it that is clogging the openings the sensor gets its air from. try taking it out and cleaning it and the connectors. don't use dielectric grease when you put it back together.

other than that, sorry i don't have any ideas. maybe there is a short in the wire?

 

[Slow5.0]

I forget to tell you guys this start hapenning on first day of snow (i drive my Stang on snow ) meybe because snow/water get's in O2 connectors (I have LTs so O2s are moved down low)

 

[Hydrocarbon]

My guess is you have a short on the STI wire which is pin #48 on the EEC 60-pin connector. Try disconnecting your computer and check for continuity between pin #44 and ground. You should see infinite resistance.

You can test your o2 sensors as well.

O2 signal test:

Let the car warm up to operating temp. Shut the engine off and disconnect the offending o2 sensor. Connect a DMM between HEGO signal and the negative battery terminal.

Restart the engine and while parked run the engine at 2000RPMs for 60sec while watching the DMM you should be seeing 0.5 volts or more.

Heres a diagram so you can find your way around the harness.

 

[Slow5.0]

My guess is you have a short on the STI wire which is pin #48 on the EEC 60-pin connector. Try disconnecting your computer and check for continuity between pin #44 and ground. You should see infinite resistance.

I didn't get this one
How I can check for continuity between pin #44 and ground, and how mucgh resistance supposed to be

And BTW does 88-91 have same EEC connector like 94-95 5.0 Stangs

 

[urban96]

nope, fox computers use a different connector then ours

 

[Hydrocarbon]

nope, fox computers use a different connector then ours

Dang

Oh well you can still test it at the STI connector. When you test the STI for continuity, it should read as an open circuit with the computer unplugged.

Edit: I meant pin #48.

 

[Slow5.0]

Dang

Oh well you can still test it at the STI connector. When you test the STI for continuity, it should read as an open circuit with the computer unplugged.

Edit: I meant pin #48.

Thats what I find out #48

BTW today I switch to spare PCM same thing, then I unplug right O2 sensor and I find little bit wet pins in connector so I have clean and dry them
BUT before I pulg again I tryed start car without right O2 BOOM, problem was gone BUT then I turn off car plug connector back start car problem is back again
I didn't try test for resistance or other testing with DMM because it was to cold out side (10F)

 

[black945.0]

maybe there is debris stuck on the connecter causing short to ground i am not sure how conductive salt is but its worth looking at

 

[Hydrocarbon]

sounds like you found the problem.