Diagnostic experts

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Diagnostic experts

Evaponly818


The neighbor is a mechanic brought this over and it failed at 15mph only. HC and NOx. He said “okay I’m sending them to get a new cat”. He already cleaned the egr passages.
I don’t know if catalyst is the issue? If it was would have failed both 15 and 25 correct?
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Re: Diagnostic experts

No One
Evaponly818 wrote


The neighbor is a mechanic brought this over and it failed at 15mph only. HC and NOx. He said “okay I’m sending them to get a new cat”. He already cleaned the egr passages.
I don’t know if catalyst is the issue? If it was would have failed both 15 and 25 correct?
Looks like it was ran cold. Try running it on manual mode and see if the numbers go down after getting it hot. If it does, wait 5-10 mins and then run it on manual mode again to see if the numbers stay down. Numbers being low at 25 is an indicator that car was ran cold or semi cold.
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Re: Diagnostic experts

Evaponly818
The car was on, idling a fair amount of time
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Re: Diagnostic experts

No One
Evaponly818 wrote
The car was on, idling a fair amount of time
Sometimes idling isn't enough for these old cars. Try pre-conditioning, then let it sit for a while and then see how it looks. Don't pre-condition and then run it, that's consider cheating on an ASM test.  
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Re: Diagnostic experts

Troll
In reply to this post by Evaponly818
A professional would send it to a shop with a dyno. Pay diagnostic fees. Have them run tests and offer a real fix.
Mr shadetree will just lob cats on it all day with the occasional degree of success.
They teach you in class to perform proper diagnosis.
You're doing a dis service to the customer, and more so- the industry.
But nobody cares-so it doesn't matter anyway.
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Re: Diagnostic experts

barrym95838
Administrator
Assuming the engine to be in decent shape (relatively speaking), I would definitely look at the actual vacuum signal to the EGR and at the O2 sensors for response time issues during dyno manual mode before checking much else.

barrym95838
EO/EI144107
“Never attribute to malice that which can be adequately explained by stupidity.”
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Re: Diagnostic experts

Best Answer I Can Give
 Damn it Troll you beat me to it.
 Sometimes you have to be Smarter than the Equipment you are working with.
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Re: Diagnostic experts

Evaponly818
In reply to this post by Troll
Well I’m not test and repair so technically I can’t do much for the customer as far as repairs go and diagnosing.
As far as this one goes I’m assuming the diagnostic tech should be somewhat advanced since it failed only at one of the speeds and not both? I could be wrong
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Re: Diagnostic experts

none
In reply to this post by No One
No One wrote
...Looks like it was ran cold. Try running it on manual mode and see if the numbers go down after getting it hot. If it does, wait 5-10 mins and then run it on manual mode again to see if the numbers stay down. Numbers being low at 25 is an indicator that car was ran cold or semi cold.
What part is cold?

It seems to me that if the engine was cold or not hot enough for closed loop that the CO would be up and not the NOx.

If the catalytic converter was cold I don't think the O2 would be at 0.0% and the CO2 at 15.9%.

15 mph is a high load so I am with Michael on this for sure. Check the EGR function and oxygen sensor response while running on the dyno at the 15 mph manual mode test.

(though, you know if you tell this to the repair shop guy he most likely won't check anything and put a new O2 sensor and EGR valve on it and blame you when it fails again because he "did everything you said.")

 
People are usually shocked when they find out I'm not a very good electrician.
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Re: Diagnostic experts

No One
In reply to this post by Evaponly818
Evaponly818 wrote
Well I’m not test and repair so technically I can’t do much for the customer as far as repairs go and diagnosing.
As far as this one goes I’m assuming the diagnostic tech should be somewhat advanced since it failed only at one of the speeds and not both? I could be wrong
Your guy is going to replace the cat, come to you with it nice and hot and its going to pass when it didn't need one. If this guy is your "buddy" id try what I suggested first before suggesting what troll or barry said.
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Re: Diagnostic experts

Evaponly818
In reply to this post by none
Thanks everyone for your initial responses and opinions
None, since you 2nd what Barry said; will this be a “lean-biased” o2 sensor meaning it’s more or less stuck on the lean side causing it to add more fuel on 15mph since it’s a higher load? Then it smoothens out at 25mph with a lighter load?
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Re: Diagnostic experts

No One
In reply to this post by none
none wrote
No One wrote
...Looks like it was ran cold. Try running it on manual mode and see if the numbers go down after getting it hot. If it does, wait 5-10 mins and then run it on manual mode again to see if the numbers stay down. Numbers being low at 25 is an indicator that car was ran cold or semi cold.
What part is cold?

It seems to me that if the engine was cold or not hot enough for closed loop that the CO would be up and not the NOx.

If the catalytic converter was cold I don't think the O2 would be at 0.0% and the CO2 at 15.9%.

15 mph is a high load so I am with Michael on this for sure. Check the EGR function and oxygen sensor response while running on the dyno at the 15 mph manual mode test.

(though, you know if you tell this to the repair shop guy he most likely won't check anything and put a new O2 sensor and EGR valve on it and blame you when it fails again because he "did everything you said.")
NONE, im just going off of experience with these cars. Paseos and tercels will fail HC and NOX at 15 and then pass clean at 25mph. I get plenty of those in my area, These cars I usually run on manual mode, watch the numbers go down  after a while, let it sit, and run it again. I test if the numbers stay down. If the numbers don't stay down after ive conditioned it, I'll send it way.

I was also looking at the CO2 and O2, def don't think its the CAT.
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Re: Diagnostic experts

Kevin
In reply to this post by Evaponly818
change the plugs and oil, and make sure the cat is HOT

On Mon, Feb 3, 2020 at 1:52 PM Evaponly818 [via Stop The Star Program] <[hidden email]> wrote:


The neighbor is a mechanic brought this over and it failed at 15mph only. HC and NOx. He said “okay I’m sending them to get a new cat”. He already cleaned the egr passages.
I don’t know if catalyst is the issue? If it was would have failed both 15 and 25 correct?


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Re: Diagnostic experts

none
My issue with getting the cat hotter than normal is that the next time it will fail again and ding your STAR score. If you do that too often you will likely have a low FPR. I sure did when the STAR scores first came out from "excessive preconditioning".

1.2.0 Before-Test-Conditions

Before the tailpipe emissions inspection an inspector must:
 
•Verify the vehicle is warmed up to normal operating temperature.  If the vehicle is not at normal operating temperature, the vehicle may either be idled (low idle) or driven normally as necessary to achieve normal operating temperature.  Normal operating temperature may be confirmed in one of the following ways:
o The coolant temperature gauge shows normal operating temperature;
o The upper and lower radiator hoses are hot and appropriately pressurized; and/or
o When applicable, the electric cooling fan cycles on at idle.

Once at normal operating temperature, continuously operate the engine at low idle for at least 3 minutes immediately prior to the tailpipe emissions inspection.  

Inspectors shall not attempt to superheat the catalyst.  Do not increase the engine RPM or load during the 3-minute idle period or during the tailpipe emissions inspection sequences except as necessary to perform the initial visible smoke snap test as described in Appendix A. Any methods used to artificially increase catalyst temperature are prohibited
People are usually shocked when they find out I'm not a very good electrician.
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Re: Diagnostic experts

barrym95838
Administrator
none wrote
Any methods used to artificially increase catalyst temperature are prohibited
... except the ones specified in the TSI "second chance".  Especially notable are the "special procedures" Ford bribed or bullied someone to add in there to artificially improve the odds ...

barrym95838
EO/EI144107
“Never attribute to malice that which can be adequately explained by stupidity.”
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Re: Diagnostic experts

No One
In reply to this post by none
none wrote
My issue with getting the cat hotter than normal is that the next time it will fail again and ding your STAR score. If you do that too often you will likely have a low FPR. I sure did when the STAR scores first came out from "excessive preconditioning".
This is why I say let it idle after the pre condition for at least 10 mins.

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Re: Diagnostic experts

dcf1ver
In reply to this post by Evaponly818
LoL many of you guys are obviously test only.

It needs a cat.

Why anyone would recommend spark plugs or any other parts when the CO2 is there plain as day is beyond me.....
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Re: Diagnostic experts

No One
That shit don't need no damn motherfucking stupid cat, it needs to be warmed up to normal operating temp. If he does was I suggested, it will pass. He just needs to make sure he doesn't run it right after he pre conditions it and let it sit a for few mins.
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Re: Diagnostic experts

dcf1ver
In reply to this post by No One
No One wrote
I was also looking at the CO2 and O2, def don't think its the CAT.
Why?
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Re: Diagnostic experts

Evaponly818
Doesn’t CO2 measure cat efficiency? Looks good up there high 15%
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