Do new MAP sensors require a calibration period?

[rawheight]

Had some work done on my 97 Buick Lesabre this past week and they decided to replace the MAP sensor (not entirely sure why, they must have run a diagnostic and found it faulty but it wasn't related to any issues I took the car in for). The engine ran fine for my short drive out of the shop, but once I got on the highway it started acting a little weird. Mostly on hills. I had the cruise control set around 74MPH and when I would hit a hill I could feel the car kind of shifting back and forth from accelerating to maintaining speed, a couple times a second. Very subtle, nothing hard but enough for me to feel it. I was really nervous at first because it felt a little bit like when my transmission went out. After about 20 minutes of driving the fluctuations seemed to subside and even out. But then when I got to my neighborhood, I had to stop at a stoplight. Coming off the stoplight the engine revved up quite a bit before it finally decided to shift into third gear.

Is this just the computer getting used to the new MAP?? Or is it possible the new sensor is faulty?? It didn't throw any codes or anything. Thanks in advance for the help!

 

[Alan 55]

Had some work done on my 97 Buick Lesabre this past week and they decided to replace the MAP sensor (not entirely sure why, they must have run a diagnostic and found it faulty but it wasn't related to any issues I took the car in for). The engine ran fine for my short drive out of the shop, but once I got on the highway it started acting a little weird. Mostly on hills. I had the cruise control set around 74MPH and when I would hit a hill I could feel the car kind of shifting back and forth from accelerating to maintaining speed, a couple times a second. Very subtle, nothing hard but enough for me to feel it. I was really nervous at first because it felt a little bit like when my transmission went out. After about 20 minutes of driving the fluctuations seemed to subside and even out. But then when I got to my neighborhood, I had to stop at a stoplight. Coming off the stoplight the engine revved up quite a bit before it finally decided to shift into third gear.

Is this just the computer getting used to the new MAP?? Or is it possible the new sensor is faulty?? It didn't throw any codes or anything. Thanks in advance for the help!

I would definitely take the vehicle back to the shop that did the work and report your concerns. This should not be happening. Just a side note, it is a good idea to ask for your old parts if a part is replaced at a shop. This may prevent the part from being discarded if it turns out that it did not actually need to be replaced.

 

[Mad_Coachman]

Had some work done on my 97 Buick Lesabre this past week and they decided to replace the MAP sensor (not entirely sure why, they must have run a diagnostic and found it faulty but it wasn't related to any issues I took the car in for). The engine ran fine for my short drive out of the shop, but once I got on the highway it started acting a little weird. Mostly on hills. I had the cruise control set around 74MPH and when I would hit a hill I could feel the car kind of shifting back and forth from accelerating to maintaining speed, a couple times a second. Very subtle, nothing hard but enough for me to feel it. I was really nervous at first because it felt a little bit like when my transmission went out. After about 20 minutes of driving the fluctuations seemed to subside and even out. But then when I got to my neighborhood, I had to stop at a stoplight. Coming off the stoplight the engine revved up quite a bit before it finally decided to shift into third gear.

Is this just the computer getting used to the new MAP?? Or is it possible the new sensor is faulty?? It didn't throw any codes or anything. Thanks in advance for the help!

Was it the MAP or the MAF? The MAP sensor measures Manifold Absolute Pressure and is located on the upper intake manifold on the left side near your serpentine belt. The MAF stands for Mass Air Flow and measures the amount of coming into your throttle body located on the right side of your engine connected to your airbox. The MAP sensor is easily broken if someone goes to replace the PCV valve that is located directly beneath it and is not careful. What did you take the car in for? By the way, I broke a MAP sensor while checking the PCV valve in my last car (2001 Lesabre Limited) and was able to glue it back together. I'm thinking that your shop went to check your PCV valve and broke the MAP sensor. MAP sensors RARELY go bad, MAF sensors DO go bad.

 

[rawheight]

It was the MAP sensor. The MAF sensor was replaced about a year ago.

I had a couple coolant leaks, one at the upper intake manifold gasket, so I finally took it in to have the upper and lower gaskets changed. I had them change the upper intake manifold as well since it had been 6-7 years since it had been replaced. They also found a leak at the thermostat housing gasket so they replaced that and found an issue with the coolant temperature sensor (it's been reading high, they found the wires barely touching under some tape) so they replaced that and repaired the wiring as well. The MAP sensor was completely separate from any issue I brought the car in for.

 

[Mad_Coachman]

It was the MAP sensor. The MAF sensor was replaced about a year ago.

I had a couple coolant leaks, one at the upper intake manifold gasket, so I finally took it in to have the upper and lower gaskets changed. I had them change the upper intake manifold as well since it had been 6-7 years since it had been replaced. They also found a leak at the thermostat housing gasket so they replaced that and found an issue with the coolant temperature sensor (it's been reading high, they found the wires barely touching under some tape) so they replaced that and repaired the wiring as well. The MAP sensor was completely separate from any issue I brought the car in for.

They probably broke the MAP sensor when they went to transfer it to the new upper intake manifold. That must have been a hefty bill. I'm guessing anywhere between 500 to 800 bucks.
Glad I'm able to do my own work. A job like that would cost me about 160 in parts excluding the MAP sensor.