Check engine light

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Check engine light

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I have a '94 base (3100) that trips a Check Engine light when deccelerating from highway speed. For example, when slowing down from approx. 70 mph, light comes on around 55-60 mph and stays on until I shut the car off. I was told that this has to do with a bad O2 sensor that was replaced.

Some time back, I disconnected the battery for about 10 minutes to try and clear the computer. This was good for a little while but, the problem returned. I tried the same thing yesterday, and no problems yet.

Anyways, if the sensor had been replaced would it still trip the computer? I tried to read the code using the paperclip trick, but didn't understand where the holes were. Can anyone tell me where I can get the codes read, and possibly cleared? I was told that I would have to go to a GM dealer, and they would charge a fortune (for the "work" that need to be done).

This might not seem like a big deal, but it basically voids the credibility of that Check Engine light.


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feelgood7777
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Check engine light

Post by feelgood7777 »

EGR valve need cleaned.  Take off the EGR, the throttle body and clean in with carb cleaner, make sure you get the little pathway into the plenum with a coat hanger or something.


1994 Adriatic Blue Z26





Mods:  GTS Solar Wing, GTS Headlight Covers, DEI 600 Amp, Infinity Kappa 4X6's & 6X9's, Viper Car Alarm, Lunar Lights, Infinity Reference 12"

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88GTRacer
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Check engine light

Post by 88GTRacer »

Quote (funk_rocker049 @ Feb. 17 2003,01:54)I have a '94 base (3100) that trips a Check Engine light when deccelerating from highway speed. For example, when slowing down from approx. 70 mph, light comes on around 55-60 mph and stays on until I shut the car off. I was told that this has to do with a bad O2 sensor that was replaced.

Some time back, I disconnected the battery for about 10 minutes to try and clear the computer. This was good for a little while but, the problem returned. I tried the same thing yesterday, and no problems yet.

Anyways, if the sensor had been replaced would it still trip the computer? I tried to read the code using the paperclip trick, but didn't understand where the holes were. Can anyone tell me where I can get the codes read, and possibly cleared? I was told that I would have to go to a GM dealer, and they would charge a fortune (for the "work" that need to be done).
Most likely the EGR valve needs to be cleaned or replaced.  Hydro carbon deposits build up and clog the valve itself, setting off the SES light.  As far as the paper clip not working...I have enclosed a link below that explains why the terminals could not be found.

http://www.bstuff.com/index.php?act=ST&f=11&t=4363

From,

88GTRacer


"It is one of the most beautiful shapes on the road. Aero, alluring and very aggressive.
It is a Beretta, the new performance coupe from Chevrolet."
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Check engine light

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Read This


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feelgood7777
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Check engine light

Post by feelgood7777 »

Is the topic pinned,  if not I think it should be, and it should be in the FAQ if not already.


1994 Adriatic Blue Z26





Mods:  GTS Solar Wing, GTS Headlight Covers, DEI 600 Amp, Infinity Kappa 4X6's & 6X9's, Viper Car Alarm, Lunar Lights, Infinity Reference 12"

Tranny # 2
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Check engine light

Post by Guest »

I too have exactly the same problem.
Can anyone throw some light as to
1)where the EGR valve is. :rock:  (steps on how to remove it will be appreciated)
2)can this problem be left alone, without causing any harm to my engine (94 base beretta 3.1)


Chazzman
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Check engine light

Post by Chazzman »

Quote (sonalbrito @ June 23 2003,20:50)I too have exactly the same problem.
Can anyone throw some light as to
1)where the EGR valve is. :rock:  (steps on how to remove it will be appreciated)
2)can this problem be left alone, without causing any harm to my engine (94 base beretta 3.1)
On a 3100 it is located on the intake, to the right of the 3100 lettering and behind the throttle body. Two or three bolts are all that hold them on.

It's not likely to cause any major problems but it certainly isn't good for the engine to be driven with the SES lamp on.


'92 GT-Z 3.1L 5spd lot's of GO FAST stuff  
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Check engine light

Post by Guest »

I agree this is a common failure--I would also reccomend you run some GM top end  engine cleaner through the intake after cleaning the egr passages

Pinned!


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Check engine light

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thx  BerettaGT/14ASEcerts & Chazzman


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Check engine light

Post by Guest »

The EGR Valve is the thing with like the three rectangle things sticking up right?





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Check engine light

Post by Guest »

yup


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Check engine light

Post by Guest »

well the egr may well be a problem.. i cleaned mine and replaced my o2 sensor and mine was still comin on "coasting" from a higher speed.
fix?
12.75 at advance
chiltons and haynes calll it the intake air temp sensor
ask for a air charge sensor.
food for thought

jim


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Check engine light

Post by Guest »

Just cleaned my EGR (hope it was the EGR )
I searched through the entire messageboard for EGR and followed the instructions.

Pictures:
1)EGR_bottom_portion_before_cleaning

2)EGR_top_portion_with_little_carbon_removed

3)EGR_after_cleaning (bad focus)

I would appreciate answers to the following questions
1) did I clean the EGR or something else ?  
2) what/where is the intake plenum?
3) how do you get the electrical connector off? I tried, failed, then left it connected and removed the EGR top half.
4) Is the "service engine soon" light the same as the "check engine" light ? I get the former.

This did not help my Idle one bit, my car still stalled at a traffic light , and the check engine light still comes on as usual.


[EDIT] Another possible symptom is that I smell gas after startup. (while I wait for the engine to warm up)

thanks





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Check engine light

Post by Guest »

You have to clean the port into the intake as well, its in the manifold where the valve bolts to (deep inside the cutout)


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Check engine light

Post by Guest »

is the "check engine light" the same as the "service engine soon" light ?

The latter comes on for the same reason for me


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