cde 44

[BigrobDog]

1990 suburban engine , 1991 1500 tbi harness.in 72 truck , i think the 91 harness has two o2 plugs. does my suburban have 2. one on each pipe, what would cause the 44 code. and how to fix.

[WIDESIDE72]

Wrong forum, imo
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[BigrobDog]

Originally Posted by WIDESIDE72

Wrong forum, imo
Posted via Mobile Device

why is that

[Lattimer]

Originally Posted by BigrobDog

why is that

Probably get more responses on the engine forum or on the 90's trucks forum.

[SS Tim]

Most of your questons and even double posts lately seem to be engine and drivetrain or pure electrical swap related.
From what I have read it does not seem like you have a factory service manual for the donor engine and electrics. A factory manual and a wire harness guide would be my first step in doing an update, not last, trying to solve "where does this go?".

[BigrobDog]

Originally Posted by SS Tim

Most of your questons and even double posts lately seem to be engine and drivetrain or pure electrical swap related.
From what I have read it does not seem like you have a factory service manual for the donor engine and electrics. A factory manual and a wire harness guide would be my first step in doing an update, not last, trying to solve "where does this go?".

i bought one for each truck , from orielly auto .but bouth were black and white and poor quality and no info , I have posted on more then one forum also electrical and sub 90 forum . thinking that i may have a better chance on the subject that nobody knows about or I am unable to find.you must be super bored cruising the forum looking for post that dont belong. But i thank u for all your help with that code 44.

people are on this site because of limited resource ,if I had all the right answers I wouldent be asking for help would I.

[WIDESIDE72]

Originally Posted by Lattimer

Probably get more responses on the engine forum or on the 90's trucks forum.

X2
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[BigrobDog]

Originally Posted by WIDESIDE72

X2
Posted via Mobile Device

your on the wrong forum

[TBONE1964]

A simple goggle search found the following information:

"This is the description of a Code 44 as set on GM products It is an indication of a lean mixture as indicated by the oxygen sensor readings.

Circuit description: The ECM supplies a voltage of about .45 volts between the appropriate terminals of the sensor. (If measured with a ten megohm DVM, this may read as low as .32 volt). The O2 sensor varies the voltage within a range of about one volt, if the exhaust is rich, down thru about .10 volt, if exhaust is lean.

The sensor is like an open circuit and produces no voltage, when it is below about 360 degrees C, 600 degreeF. An open sensor circuit, or a cold sensor, causes Open Loop operation.

Test description:

1.) Code 44 is set when the O2 sensor signal voltage remains below .3 volts for 50 seconds or more and the system is operating in "closed loop".

Diagnostic aides:

The code 44 for lean exhaust is most likely caused by one or more of the following:

1.) O2 sensor wire - Sensor pigtail may be mispositioned and contacting the exhaust manifold.

2.) Check for an intermittent ground wire between connector and sensor.

3.) Poor ECM to engine block ground.

4.) MAF Sensor - A MAF sensor that causes the ECM to sense a lower than normal airflow will cause the system to go lean. Disconnect the MAF sensor. If the lean condition is gone then replace the MAF sensor.

5.) Vacuum leaks can cause a lean condition and/or possibly a high idle. Check for cracked hoses a bad gasket or a faulty EGR or PCV Valve.

6.) fuel pressure - system will go lean, if pressure is too low. It may be necessary to monitor fuel pressure while driving the car at various road speeds and/or loads to confirm.

7.) Clogged injector or lean injector - perform an injector balance test.."

Try a factory GM service manual. They are much more accurate than the ones sold at Oreiley's

[SS Tim]

Originally Posted by BigrobDog

i bought one for each truck , from orielly auto .but bouth were black and white and poor quality and no info ,...

Please note I said "factory". Really doubt that you found those at O'Riellys. They will have complete wiring diagrams and diagnostic tables to help with code and wiring issues on stock vehicles (as a note my 99 Camaro set totals almost a foot thick). To sucessfully itegrate a late harness and controls into an earlier vehicle you need to have a good understanding of both vehicles and their systems.

In all fairness I was trying to answer your question "why is that" earlier. Having seen your posts/questions go unanswered and seemingly out of place I though it deserved an answer.

As far as DTC 44: Oxygen Sensor (HO2S) Circuit (Lean Exhaust Indicated) There can be many causes on a stock installation. You questions seem to idicate you are not sure what a stock installation even is, hence the recommendation to buy some documentation. As to what the stock installation is and the differences between a 90 and a 91 Chevy truck I don't know and can't help you. However a consumer Mitchell DIY subscription for a 92 C1500 will give you a great deal of information to help you sort through this.

But remember if the ECM is expecting a O2s signal that is out of limits or not there you are going to get code. In order for the system to run correctly it will need to see a feedback signal from the O2 sensor/s to correct the PWM of the injector for a given engine speed, load, temp and altitude.

[SS Tim]

This link should help you out.
http://67-72chevytrucks.com/vboard/s...d.php?t=545416

[BigrobDog]

Originally Posted by SS Tim

This link should help you out.
http://67-72chevytrucks.com/vboard/s...d.php?t=545416

thanks tim but when i click on link it says it cant be found .

[SS Tim]

Sorry something is wrong with the first link here try this.
http://67-72chevytrucks.com/vboard/s...d.php?t=545416