Ok, heres the deal. I had to tak emy car in to get scanned after throwing a SES light. Got an infamous code 44 (Lean Condition), this bonehead is trying to tell me I got the wrong MAP sensor. This is the same MAP sensor thats been in the car for over three years now (at least since I owned it) with never a problem. I am not getting a bad MAT reading or code. He seems confused because it has a solid element at teh tip just like the CTS. So I go to a local auto store (not AutoZone or any of those other idiot places) He pulls the sensor for an 88 350, looks exactly like what I have (sensor on left in pic). So we decide to pull another one for an 87' 305, what we got was the sensor on the right in pic, which has more of an open element at the tip.

So those of you who are familiar or maybe have a picture of one from the book (Trickster) chime in. Is this what yours looks like? I am so upset I could hardly sleep, now this guy has my car apart and I just want it back. Can't stand taking my car to somebody else. Oh and worse when I wanted to debate with him about the sensor I get the, I've been doing this for 30 years now I think I know what I am talking about crap. I hate that. Ok done ranting.

 

If it's in the plenum it is the one on the left....if it is in the air duct it is the one on the right I think, usually that is the case.
HTH

 

I purchased the one on the left for my '88 TPI setup, and it works fine. Echlin part from Napa.

I've seen the "open element" one before, but I can't recall if it was the original piece on my setup, or if I grabbed it from something else.

You know, if these types of things bother you, Napa's Echlin catalog of sensors is a darn good resource. (have to go to the store to look at it) In many cases it shows the circuitry of the sensors, the pinout, and however it's operation is measured. Such as the ohm ratings of a 60 PSI oil pressure sending unit vs. an 80 PSI unit, or the temperature range of a fan temp switch.

 

Thanks guys. The only thing that bothers me about it is the mechanic thinking he knows everything, which I would appreciate if it was true. The one on the left is apparantly the correct one I just wanted some more verification on it. The parts catalogue we used also showed this part. So I will take it back to him tell him to put my friggin car back together and never take it back there. I need a scanner.

 

I Think you might like to read this

Bill

CODE 44 - OXYGEN SENSOR CIRCUIT (LEAN EXHAUST INDICATED)

Circuit Description:
The Electronic Control Module (ECM) supplies a voltage of about .45 volt between terminals "D6" and "D7". (If measured with a 10 megohm digital voltmeter, this may read as low as .32 volt.) The 02 sensor varies the voltage within a range of about 1 volt if the exhaust is rich, down through 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 degrees F) An open sensor circuit or cold sensor causes "Open Loop" operation.

Test Description: Numbers below refer to circled numbers on the diagnostic chart.


Code 44 is set when the 02 sensor signal voltage on CKT 412 remains below .2 volt for 2O seconds and the system is operating in "Closed Loop".
Diagnostic Aids:

Using the "Scan", observe the block learn values at different rpm and air flow conditions. The "Scan" also displays the block cells, so the block learn values can be checked in each of the cells to determine when the Code 44 may have been set. If the conditions for Code 44 exists the block learn values will be around 150.

02 Sensor Wire. Sensor pigtail may be mispositioned and contacting the exhaust manifold. Check for intermittent ground in wire between connector and sensor.

Mass Air Flow (MAF) Sensor. A Mass Air Flow (MAF) sensor output that causes the ECM to sense a lower than normal air flow will cause the system to go lean. Disconnect the MAF sensor and if the lean condition is gone, replace the MAF sensor.

Lean Injector(s). Perform injector balance test CHART C-2A.

Fuel Contamination. Water, even in small amounts, near the in-tank fuel pump inlet can be delivered to the injectors. The water causes a lean exhaust and can set a Code 44.

Fuel Pressure. System will be 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, See "Fuel System Diagnosis", CHART A-7.

Exhaust Leaks. If there is an exhaust leak, the engine can cause outside air to be pulled into the exhaust and past the sensor. Vacuum or crankcase leaks can cause a lean condition.

AIR System. Be sure air is not being directed to the exhaust ports while "Closed Loop". If the block learn value goes down while squeezing air hose to left side exhaust ports, refer to CHART C- 6.

If the above are OK, it is a faulty oxygen sensor.

 

I may be wrong but, I think the man is taking you for a ride!

Bill

 

The one on the left, as mentioned by several other members of the board, is the correct one used in our cars. That same one is also used in the 305 TPI engine. I had to make a stop at the local dealership this morning so while there I asked a buddy in the parts room and he brought one out and showed me. The one on the right in your picture appears to be an aftermarket unit or as also mentioned. One that goes on a TBI car. I am also curious as to why he would say you have the wrong MAP sensor when your car has the MAF sensor unless you converted over to MAP. And you are asking about the MAT sensor? I am with elcaminO_77us. I think you need to get your car away from him fast and don't go back. Especially if he doesn't know the difference between a MAP sensor, a MAF sensor, & a MAT sensor.

 

The one on the left is the correct one. Tell buddy with his 30 years experience to stick it where the sun don't shine!

 

Yeah Trickster I just re-read my post that I put up in a fired up hurry this morning. These are MAT's as stated in my title to the post, my brain must have had a fart and I typed MAP instead of MAT in the post. I am in total agreement this guys a slug. I am having the hardest time here trying to find a mechanic who is familiar with these cars. I do most work myself but I don't have any scanning equipment right now so I took it in to get scanned and blamo here I am wishing I hadn't. Thanks for everything all. I'm on my way over there now.

 

How doe's the car run?
Any hesitation,stumbling, stalling?
Hell it could be the fuel pump.

 

Hi, I running this week a 91 trans with a 305 TPI, and I also have the code 44. First I suspect about the O2 sensor, but the car going in closed loop, and when is cold run very well, but when is hot is when the problems become. If I go to wot it run well, but at partial gas appear that hesitate and I feel a big loose of power.
Another symptom is that the converter lock up is on in the same moment I don't move the gas, even at about 30-40 mph in slowly acceleration. This code is no much precise and I am crazy with it.

where is the order to the converter lock up from? Perhaps the TPS?
Could a malfunction of the tps cause this?

Escuse me for all you if I can not explain very well, I am Spanish, and as you can see English is very hard to me. Sorry.

 

The converter is mostly controlled by the vehicles speed. TPS plays a very small role in that it will sence more throttle and unlock. A car will run fine with a bad MAT or even missing. With a code 44 I would go with a new 02, even though its going into closed loop. Its a cheap 30 bucks investment also. Remember to use some antiseize when installing the new one.

PS Man this is an old post lol.

 

Edited..

 

That's O.K. - My Spanish is not all that great, but we'll get it done.

1. The Vehicle Speed Sensor (VSS) inputs road speed to the ECM (computer).
2. The distributor inputs engine RPM to the ECM.
3. The Manifold Absolute Pressure sensor (MAP) reports vacuum to the ECM.
4. The Throttle Position Sensor (TPS) reports throttle angle to the ECM.

The engine RPM, TPS, and MAP are used by the ECM to calculate engine load, a factor called "Load Variable" or LV8, for short. The vehicle speed (VSS) and load (LV8) are used to determine the Torque Converter Clutch (TCC) lock or unlock status, along with some time delays to prevent rapid lock and unlock.

Therefore, somewhat indirectly, the TPS does have a bearing on the TCC operation.

 

This car was siting about one year since I got it, but I don't know if with the previous owner the car was running, or also was siting a lot of time. Certainly, with the first tank I fill I found a bad gas milleage, about 12-13 mpg., I refill, and for now appear that the gas milleage is better, but I dont know how much better yet. Today the car not fail, but today here all day was raining.
The TCC ( ) continue lock and unlock with very much frecuence when I go about only 35-40 mph. with only a little of gas or with very low acceleration. I certainly dont know if this could be normal or not, but I have other automatic cars (also with lock up) and dont work like this.
That was for why I made the question about where come from the order to lock and unlock the TCC.
As I understand the diferent sensors work, I think that those code 44 could be for the O2 sensor itself, Perhaps a TPS that not working uniformly could be the cause of the code 44 and a innecesary lock-unlock TCC??

This is my second F-body, but the first (73 Camaro) is too much easy to work and diagnose that this

My first plan for now, is to change the O2 sensor, like Mkos1980 said (thanks) and then........ I will see what happen.

Thanks very much for the help.

Fran.

 

TPS has a BIG effect on torque converter lockup, actually.
VSS has a BIG effect on torque converter lockup, too.
Engine temperature must also be above about 120F.

That's about all the input TPI cars use for lock/unlock. No load. No RPM even.

If it runs well at WOT, but not part throttle, it's your O2 sensor's fault. Check the wires to it, near the sensor, to make sure it's connected, and not grounded. Check the exhaust for a huge hole there (won't be, but never know until you check). Then replace the sensor.

TPS could be your problem of the TCC. Probably not causing the 44 though.

 

I sampled a two 1991 TPI programs. The TCC lockup and unlock points are programmed at 30/32 MPH minimum, depending upon load value and engine RPM. It seems that your lockup could be completely normal.

The error code 44 could improve after some more driving. Once the oxygen sensor gets heated fully and burns off contamination, the sensor may start generating a better signal. It is also possible the sensor is already damaged and may never work properly again. A new sensor would solve that question.

 

Are there any preferred manufacturer for the O2 sensors?
I will buy it in Rockauto and they work with AC Delco, Standard motor products...... etc.

 

Delco 02 choice #1

Denso choice #2

Stay away from bosch as they have known issues as far as compatability to our stock ones.

 

Getting back to the original MAT sensor question, both of the units pictured have been used on TPI equipped Fbodies.

The unit on the left was the MAT/IAT (whatever you want to call it), on 86-92 TPI engines. It also happens to be the same part number as the coolant temperature sensor for 85-92.

The unit on the right was the MAT/IAT for 1985 TPI engines. With the exception of the connector that mates with it, they are interchangeable.

 

Well, I solved my problem with the TA, I change the O2 sensor, and the fuel filter and not fail anymore.