1996 ForRanger 2.3 Won't Set Readiness For 02 / Cat FIXED

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CalRewireMatt
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1996 ForRanger 2.3 Won't Set Readiness For 02 / Cat FIXED

Post by CalRewireMatt »

Im really scratching my head on this one. Have a 96 Ranger 2.3 that wont pass emmisions due to monitors not completing for O2, O2 Heater and Catalyst. Before it showed up here, the front and rear o2's, CLT(dunno why), MAF as well as the PCM which I have verified has an up to date calibration per Motorcrafts website have been changed. All other monitors have set and no codes other than P1000 is present.

According to EASE, this truck doesn't have Mode $06 data to watch so Im stuck with data stream info only. KOEO and KOER tests dont report any codes back nor is there anything pending. The scan data states that I have performed 7 OBD2 drive cycles with a half tank of gas utilizing every different method I can think off in order to set these fkn monitors and it just flat out refuses to work.

The front O2 switches fairly decently when warm and the rear is planing around 400mV and is quite a bit slower so it appears that things are at least at first glance to be operating as they are supposed to. I did note that the LTFT is +7% which is a bit higher that Id like but not out of the ordinary for an old truck IMO.

So, have any of you guys run into this situation or one similar on these that had a solution? Im running out of things to check and would like to get this thing out of my life.
Last edited by CalRewireMatt on Tue Jul 16, 2013 3:33 pm, edited 1 time in total.
Tim Martin
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Re: 96 Ranger 2.3 wont set readiness for 02 or Cat

Post by Tim Martin »

I had one of those several years ago an it gave me a royal fit. I took it out one night, had the OBD Drive Cycle Sheet along and followed it to the T. After 3 hours I finally got it to reset all the readiness monitors. An, yes the customer got charged for 3 hours of my time. But the Fords of those years could at times be a real pain to get to reset.

I presume in your area all the monitors need to be reset. Here in PA where we are, we could run it through if all but 2 of the monitors were reset. Gives us some flexibility. hth
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ricmorin
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Re: 96 Ranger 2.3 wont set readiness for 02 or Cat

Post by ricmorin »

I'm sure you checked the obvious, but I'll run through some common things......

1. Fuse for KAM. Sometimes this blows and monitors reset every key cycle.
2. For cat to run, the O2's run and pass first. I think your post says the O2's were replaced? If so, with what quality? Sometimes the heater elements are off and the monitors won't initiate with poor quality sensors.
3. Coolant and intake temps.....these have to be within spec for monitors. Between 40 and 100 on IAT and over 180 on the CTS. If it falls out of range, the monitor stops.
4. Early OBD2 Fords are a * to get the monitors to run. I've seen it take over 1000 miles. Nice design. Those were the wild wild west days of emission controls.

Have you run the drive cycle to the letter?
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CalRewireMatt
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Re: 96 Ranger 2.3 wont set readiness for 02 or Cat

Post by CalRewireMatt »

Tim Martin wrote:I had one of those several years ago an it gave me a royal fit. I took it out one night, had the OBD Drive Cycle Sheet along and followed it to the T. After 3 hours I finally got it to reset all the readiness monitors. An, yes the customer got charged for 3 hours of my time. But the Fords of those years could at times be a real pain to get to reset.

I presume in your area all the monitors need to be reset. Here in PA where we are, we could run it through if all but 2 of the monitors were reset. Gives us some flexibility. hth
In CA, you can also have 2 monitors failed/incomplete.
CalRewireMatt
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Re: 96 Ranger 2.3 wont set readiness for 02 or Cat

Post by CalRewireMatt »

ricmorin wrote:I'm sure you checked the obvious, but I'll run through some common things......

1. Fuse for KAM. Sometimes this blows and monitors reset every key cycle.
KAM is good as is the battery. All other monitors stay set as complete
2. For cat to run, the O2's run and pass first. I think your post says the O2's were replaced? If so, with what quality? Sometimes the heater elements are off and the monitors won't initiate with poor quality sensors.
I was think the same thing about that. Logic being, if you cant trust the O2s then you cant properly test the cat. I dunno what brand sensors they are and I think you may be on to something as they could be junk from Pepboys that were purchased by cost alone. I may change them out for known good parts just to be sure and then retest.
3. Coolant and intake temps.....these have to be within spec for monitors. Between 40 and 100 on IAT and over 180 on the CTS. If it falls out of range, the monitor stops.
Coolant is in spec, as far as IAT is concerned, is that starting the test or it must stay under 100 at all times?
4. Early OBD2 Fords are a * to get the monitors to run. I've seen it take over 1000 miles. Nice design. Those were the wild wild west days of emission controls.

Have you run the drive cycle to the letter?
As best as I can with the roads I have at my disposal. I can normally get O2 and O2 heater readiness within the first leg of my rout I normally drive which is ~6 miles so long as there isnt a problem.
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Re: 96 Ranger 2.3 wont set readiness for 02 or Cat

Post by CalRewireMatt »

FIXED!

Never assume "new" parts are that. Since you guys brought it up I decided to take the sensors out and look at them. Rear O2 was a Bosch sensor and sensor looked nice and new. The front sensor was the ORIGINAL sensor and the mechanic before wiped it down so it appeared new but was far from. The sensor head was totally white with a very sooty spot on one side and was obvious that the sensor was either new to the truck but from another truck or it was never replaced.

So I replaced the front O2 and did my drive cycle which set all readiness after the first leg of my route just like normal.

Thanks guys, woulda kept staring at other things and never figured that a mechanic would do something like that when he had obviously changed a lot of other parts.
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Re: 96 Ranger 2.3 wont set readiness for 02 or Cat ***FIXED

Post by Tim Martin »

Thanks for letting us know the fix. And, yes, your find is another reminder that in our diagnosis we should not assume the customer is telling the correct story. Also, do not assume that what the customer says is new may not be the same definition for us.

Good job!!!!!!
CalRewireMatt
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Re: 96 Ranger 2.3 wont set readiness for 02 or Cat ***FIXED

Post by CalRewireMatt »

Tim Martin wrote:Thanks for letting us know the fix. And, yes, your find is another reminder that in our diagnosis we should not assume the customer is telling the correct story. Also, do not assume that what the customer says is new may not be the same definition for us.

Good job!!!!!!
Thanks much, Ive had it I the shop for 2 weeks and I did find that the "mechanic" before got the firing order wrong on the dual plug motor causing a misfire and was setting a misfire #2 code but even after that, the damn truck was kicking my butt.

This is the 2nd of 4 times I have posted to the forum for help only to ultimately find out that my diagnostic skills were being thwarted by the assumption that proper parts had been changed. We have a rule of not listening to another shops diagnostic results because if they were able to properly diagnose issues, the car wouldn't be in the shop to begin with. I will add to that rule that we will not trust any part as well.

Thanks again!
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steven kiser
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Re: 96 Ranger 2.3 wont set readiness for 02 or Cat ***FIXED

Post by steven kiser »

Thanks for posting the fix. Like you said, never trust another shops diagnosis or repair. Years ago I started to insist that if a vehicle came into my shop with driveability issues and it was worked back to work that was performed at another shop there is two options. Pay me for my time or allow me to remove all the installed parts at my disgression and replace with ones of my choice. What made me make that decision was a vehicle came in that just had been tuned up with a skip. We found a spark plug that had a closed gap. We replaced it and sent it on it's way. A week later it was back with another issue and we found that the three rear plugs hadn't been changed and one was misfiring. In the customer view it was my issue since it was last in my shop. Suddenly I was responsible for the other shops issues since in his words "you were paid to straighten out their mess". From that day on there were times when people left with boxes of parts that had been installed at other shops.
never argue with a fool, they'll drag you down to their level and beat you with experience
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Re: 96 Ranger 2.3 wont set readiness for 02 or Cat ***FIXED

Post by Tim Martin »

Initially I am thinking "Whoa Whoa Steve, yer taking things to a new level" but ya know, your approach is part of what i use as well. I typically dont replace all the parts previous shops installed but I will remove them to see if what the customer says is correct. More often than not it aint what the customer says it is. So, now, in addition to wearing all the hats we do, we add detective to our list.
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