Smog - 95 Pontiac Grand Am 6-cyl

Tiny
BAOBABGIRL
  • MEMBER
  • 1995 PONTIAC GRAND AM
  • 6 CYL
  • AUTOMATIC
I have a 95 pontiac grand am. The mechanic has replaced the egr valve. And also put new catalytic converter on. I don't have the smog results with me (at the mechanic's right now) - but it passed everything but the top # on the NOX. And then when tested again - it passed everything except the bottom # on the NOX. Any other ideas?
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Tuesday, January 4th, 2011 AT 11:37 PM

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Tiny
SATURNTECH9
  • EXPERT
If your getting bad nox reading's and the egr was replaced I would be checking to see if the egr port's are clogged. Do you have any code's?
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Tuesday, January 4th, 2011 AT 11:53 PM
Tiny
BAOBABGIRL
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Thanks - I don't know - the engine light did come on a couple of days after the egr was replaced - but I don't think the codes were ever rechecked
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Wednesday, January 5th, 2011 AT 12:08 AM
Tiny
SATURNTECH9
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Well I would start with what code's were set when that light came on. Let me know the exact code number's your car has.
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Wednesday, January 5th, 2011 AT 12:28 AM
Tiny
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I just went to pick up my car - it was still not smogged - and when I asked the mechanic about the check engine light - he said there were no codes. The check engine light was about 3-4 weeks ago before I left the car at the mechanic's shop before Christmas - so - has it had enough cold starts to get rid of the codes? Anyway - I don't have the codes
I'm desperate to know what's going on - the next thing they said was the oxygen sensor - they said they've seen a lot go out on cars. And mine is a 1995. With about 300k miles
If it is the oxygen sensor - do you have any numbers on how much to replace it?. It's so great to have someone to ask about this!
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Wednesday, January 5th, 2011 AT 2:28 AM
Tiny
SATURNTECH9
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I would say the o2 sensor is probably bad if it was the one the car came with. But to say replacing it will make your car pass smog that's another thing.I would lean more to a clogged egr port since you have 300,000 mile's on the engine.I have seen car's with a lot less mile's have clogged port's. Since you said the nox reading's are off and the egr help's reduce them I would be looking at the egr.A lot of the time I have seen people have egr code's and just replace the egr valve without checking to see if the egr port is clogged. Do you have a friend that can remove the egr valve to check that port?If so I can tell you how to check it.
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Wednesday, January 5th, 2011 AT 6:06 PM
Tiny
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The mechanic said he cleaned the ports when he replaced the egr valve - what do u think
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Thursday, January 6th, 2011 AT 6:46 AM
Tiny
SATURNTECH9
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So was the egr replaced because of a code the car set or because of the nox reading being off?Also after the repair's did he reset all the monitor's before testing it for smog?I would still test to see if the egr port was clogged just to be on the safe side since your dealing with nox reading's being off.
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Thursday, January 6th, 2011 AT 9:06 PM
Tiny
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The egr was replaced because of a code - I dont know if he reset ALL? The monitors? What do you mean. Monitors?
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Monday, January 10th, 2011 AT 8:52 AM
Tiny
SATURNTECH9
  • EXPERT
Whenever you get a code replace certain part's battery die's etc the car has to go thru a drive cycle to relearn what's called the monitor's for emission's component's. SO you know for sure the egr passage's are clean if they aren't it will throw off your nox reading's.
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Monday, January 10th, 2011 AT 6:32 PM
Tiny
BAOBABGIRL
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OK - I went over to my mechanic this morning as the engine light was coming on. And got them to look at the codes. There was a HISTORY of codes. But no new codes for today - and they just disconnected the battery (which we had done before but probably not long enough) to get things to reset.
The code history was:
#76 - EGR for fuel port 2
#77 - EGR for fuel port 3
#35 - improper idle & possible IAC?
#54 - fuel pump?

So - for #76 & #77. The EGR was replaced - and mechanic says the ports were cleaned
for #35? Was told that 'that' has nothing to do with getting car smogged
#54. Fuel pump? Don't know what that code really means

I ALSO WENT OVER TO THE LAST (4th) smog guy and he (as well as my mechanic) said that it could be
- oxygen sensor?

He also said - have the fuel pressure regulator checked. Could be clogged fuel filter?

He said the mechanic has a tool to check the oxygen sensor
and also another gauge for the fuel pressure regulator

A new catalytic converter - was already put on. And still didn't pass. Thus the questions and update - so WHAT DO YOU THINK after this info?
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Monday, January 10th, 2011 AT 11:11 PM
Tiny
SATURNTECH9
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If this guy has a o2 sensor tester which they do make them have him test it's probably going to test bad because of the mileage. So which code did he say was turning the check engine light back on?So the guy that fixes your car just take's the battery cable's off to clear the code's?He doesn't have a tool to do that?What doesn't make sense is when I asked you about codes you said you asked about that and were told you have none. Did he check for code's then?Because now you have all these code's come out of no where that are suppose to be history code's from the egr repair. Make's no sense to me. The 76 and 77 has to do with the egr valve the 35 has to with the idle air control valve that control's your idle. Here's the funny thing that code 54 that he said you could have a clogged fuel filter or bad fuel pressure regulator I think I would find a new guy to fix my car. Here is the code description for code 54 it's for the fuel pump electrical circuit not fuel pressure or flow. You can read it for yourself.
CIRCUIT DESCRIPTION
The status of the fuel pump circuit 120 is monitored by the Powertrain Control Module (PCM) at terminal "A6." The voltage signal is used by the PCM to determine actual fuel pump speed and therefore fuel pressure. This information aids in determining correct injector pulse width for fuel delivery. Diagnostic Trouble Code (DTC) 54 enables the technician to determine if a circuit or relay error has occurred in the fuel pump circuit. This diagnostic trouble code occurs any time a voltage less than the calibrated minimum value has been sensed on circuit 120. Diagnosing extended crank time or "Cranks But Won't Run" is aided with this DTC.

DTC 54 WILL SET WHEN
Fuel pump voltage at terminal "A6" is above 14 volts or below 7 volts for 3 seconds.

ACTION TAKEN (PCM) WILL DEFAULT TO
The oil pressure switch will provide a current path for the fuel pump when oil pressure becomes great enough to close the contacts. The Malfunction Indicator Lamp (MIL) will become illuminated.

DTC 54 WILL CLEAR WHEN
A current DTC 54 will clear when voltage at the fuel pump monitor is sensed within the calibrated voltage threshold. A History DTC 54 will clear after 50 consecutive ignition key cycles without a current DTC 54 being stored.
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Monday, January 10th, 2011 AT 11:50 PM
Tiny
BAOBABGIRL
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THANKS - YOU GUYS ARE GREAT. Here are my answers to your questions:

If this guy has a o2 sensor tester which they do make them have him test it's probably going to test bad because of the mileage. So which code did he say was turning the check engine light back on?

- he didn t find a code turning the check engine light back on. It just looked like it didn t clear from the time he put in the NEW EGR valve so this time he unhooked the battery for a couple of minutes instead of a short time

So the guy that fixes your car just take's the battery cable's off to clear the code's?

- yes besides putting on the new egr valve

He doesn't have a tool to do that?What doesn't make sense is when I asked you about codes you said you asked about that and were told you have none.

- no I said I didn t have the codes myself as I had not asked for them this time I asked and found out what the history of codes were. And those four codes that I told you about were the only ones showing up this morning

Did he check for code's then?Because now you have all these code's come out of no where that are suppose to be history code's from the egr repair. Make's no sense to me.

-. Simple misunderstanding with time delays. The codes are not new no new code for today just the history of codes showed up

The 76 and 77 has to do with the egr valve

- yes I know that because it showed for ports # 2 and #3. And that s why he put in a new EGR valve

the 35 has to with the idle air control valve that control's your idle

-interesting. Because I have a real problem on cold start s. The engine rev s toooooo high. And then calms down once the car is going

Here's the funny thing that code 54 that he said you could have a clogged fuel filter or bad fuel pressure regulator I think I would find a new guy to fix my car. Here is the code description for code 54 it's for the fuel pump electrical circuit not fuel pressure or flow

-OK. FOR CODE 54. I just had the FUEL RAIL LINE REPLACED A MONTH OR SO AGO. Sounds like they didn t set it right? Thoughts on this as it affects SMOG?

Since new EGR put in. And ports cleaned - new catalytic converter. DO YOU THINK CODE 54 might be it?

THANKS SO MUCH!
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Tuesday, January 11th, 2011 AT 12:28 AM
Tiny
SATURNTECH9
  • EXPERT
Code 35 will have to be looked at for that high idle could even be a vacuum leak. You mention the fuel rail line was replaced well if you read the code 54 description it say's DTC 54 WILL SET WHEN
Fuel pump voltage at terminal "A6" is above 14 volts or below 7 volts for 3 seconds.A fuel line won't cause voltage to be above 14 volt's or below 7 volt's to terminal A6 of the fuel pump relay right?There is a trouble tree that list's all kind's of thing's but none of them is for fuel pressure or flow. It's a electrical code.I doesn't see that problem skewing your nox reading's.
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Tuesday, January 11th, 2011 AT 12:50 AM

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