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Old 07-30-2004, 08:11 PM
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emissions

hey, anyone out there that lives in an area that has those peskie emissions tests...

just had my car inspected... emissions failed... mechanic had no time to diagnose prob, thought it could have been O2 sensor but that was replaced 20 - 30K ago... the limits are (and i think) 120 - my car read 400+ at idle and around 200 at 2500 rpm...

short of taking it to satan anyone have any ideas as to what might cause readings this high

also anyone out there ever use that stuff "guaranteed to pass emissions" stuff and does it work?

HELP PLEASE!
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Old 07-31-2004, 06:14 AM
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Originally Posted by charbroiled91
hey, anyone out there that lives in an area that has those peskie emissions tests...

just had my car inspected... emissions failed... mechanic had no time to diagnose prob, thought it could have been O2 sensor but that was replaced 20 - 30K ago... the limits are (and i think) 120 - my car read 400+ at idle and around 200 at 2500 rpm...

short of taking it to satan anyone have any ideas as to what might cause readings this high

also anyone out there ever use that stuff "guaranteed to pass emissions" stuff and does it work?

HELP PLEASE!
What were the readings of? Hydrocarbons? CO? NOx? That will help diagnose what could be going wrong.
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Old 07-31-2004, 06:30 AM
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all the readings were normal or way below except for the hydrocarbons...

state acceptable limit on HC's are 220

mine at idle (842 rpm) were 442

............. at 2649 rpm were 211

CO% at idle (842 rpm) limit 1.2 ... mine .40

............. at 2649 rpm limit 1.2 ... mine .23

Dilution at idle (842 rpm) reading 15.1

............. at 2649 rpm reading 14.9

I have no idea what or how to read this crap so any and all info is helpfull...
I have yet to check to see if i have a bad injector (or two) so i'm gonna start there
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Old 07-31-2004, 06:57 AM
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Hydrocarbons?

02 sensor and maybe some new plugs.

But, at least the 02 sensor.
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Old 07-31-2004, 07:10 AM
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I odn't know why, but last time I ran my emissions, with a bad o2 I had was really clean.
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Old 07-31-2004, 08:38 AM
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[mechanic had no time to diagnose prob, thought it could have been O2 sensor but that was replaced 20 - 30K ago...]

can those go bad in that short of time???
and am i correct in that the resistance reading of a properly functioning injector is +/-10 ohms?
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Old 07-31-2004, 08:56 AM
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Originally Posted by charbroiled91
[mechanic had no time to diagnose prob, thought it could have been O2 sensor but that was replaced 20 - 30K ago...]

can those go bad in that short of time???
and am i correct in that the resistance reading of a properly functioning injector is +/-10 ohms?

A Properly running injector should read between 10-14Ohms (at least for VE engine, I am guessing VG is the same or close). If an injector is causing the engine to run rich, then an O2 sensor can surely go bad in 30k if it is being exposed to all that excess fuel all the time. Same with the catalytic converter. Looking at the numbers, I don't think it is the O2 sensor because CO is good while HC are bad. Those usually go hand in hand when the O2 sensor is bad. Definitely check those injectors. If they are leaky, chances are your cat is destroyed too by all the raw fuel passing through it. Check out my emissions report from where I failed NOx twice.



The bottom data is when the cat wasn't properly warmed, notice how the hydrocarbons are higher and mirror the CO2 output more closely. In the top set of data the cat was hot from coming off the highway and HC and CO were significantly lower.
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Old 07-31-2004, 09:17 PM
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I am pretty sure it's your EGR valve and it's a possibility that your cat converter substrate were all rotten. just go jerryromenissan and get yourself a new EGR valve, man. o2 don't go out that early. they should last you 60k. it could also be your cat converter too. again, those should last around 60k+.
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Old 08-01-2004, 08:41 AM
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Originally Posted by bvtran
I am pretty sure it's your EGR valve and it's a possibility that your cat converter substrate were all rotten. just go jerryromenissan and get yourself a new EGR valve, man. o2 don't go out that early. they should last you 60k. it could also be your cat converter too. again, those should last around 60k+.

Which person are you talking to? If you are talking to him, then the EGR valve has nothing to do with hydrocarbons. It is for reducing NOx only, believe me I know. For me, it was not the EGR valve itself but the vacuum source that opens and closes it.

P.S. I have a working EGR valve for sale if you decide not to take my advice.
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Old 08-04-2004, 04:39 PM
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Ok... new information...
i took my max to Pep Boys and here's what they told me (after i shelled out yet another $90+)

my catalytic converter is not heating up enough to burn off the HC's... that's why it's reading lower at high rpm... the service manager told me that the cat needs to be at around 500 degrees F in order to function properly and mine at idle was only around 200. He also told me that the reason was because my intake and exhaust were too large to restrict enough air to properly heat it up.

the only mod i did to the intake was to remove the factory airbox and replace the whole thing with a APC Filtercharger mounted right at the MAF. my cat is 2.5" in flow diameter and the B pipe is 2.5" all the way to the 3" magnaflow muffler. I didn't think these mods were that drastic to cause this much friggin headache.

The service manager said if i can somehow restrict the airflow right after the cat that it would be able to heat up enough to remedy this for inspection.

Oh and he also told me there was absolutely nothing wrong woth any of the above EGR or O2 and thye Cat was working fine.

Any input...
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Old 08-04-2004, 05:31 PM
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Originally Posted by charbroiled91
Ok... new information...
i took my max to Pep Boys and here's what they told me (after i shelled out yet another $90+)

my catalytic converter is not heating up enough to burn off the HC's... that's why it's reading lower at high rpm... the service manager told me that the cat needs to be at around 500 degrees F in order to function properly and mine at idle was only around 200. He also told me that the reason was because my intake and exhaust were too large to restrict enough air to properly heat it up.

the only mod i did to the intake was to remove the factory airbox and replace the whole thing with a APC Filtercharger mounted right at the MAF. my cat is 2.5" in flow diameter and the B pipe is 2.5" all the way to the 3" magnaflow muffler. I didn't think these mods were that drastic to cause this much friggin headache.

The service manager said if i can somehow restrict the airflow right after the cat that it would be able to heat up enough to remedy this for inspection.

Oh and he also told me there was absolutely nothing wrong woth any of the above EGR or O2 and thye Cat was working fine.

Any input...

That sounds like hor$e$hit to me. How long do you warm the car up before you go and get it tested? Make sure you drive around for 20 minutes before the test, and let the car idle if you have to wait in line. I can't possibly see how an intake and exhaust would cause those problems. If anything, they allow for more fuel to be burned, which in turn would make the exhaust hotter than before. At least you have the problem isolated to the cat.
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Old 08-05-2004, 03:56 PM
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That's why I will never take my car to Pep Boys, they are full of it.
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