I feel like I'm getting nickel and dimed with this damn thing.

I bought the car used, on recommendation from a mechanic friend of mine.

To make a long story short. My mechanic friend replaced the TPS. about a year later a different mechanic replaced the TPS unit again. Then the MAFS was replaced, by me, on recommendation of my mechanic friend. Just had the TPS unit replaced a 3rd time while car was in the shop on an unrelated issue.

What is going on here?

are the sensores actually being tested as bad, or is it just assumed that they are bad? not to discredit your mechanic friend, but sometimes even a very good mechanic can overlook a problem that can seem like something else.

Are you getting good quality pieces, or just the cheapo ones?

I would check the battery cables and all their connections for any amount of corrosion. These cables and grounds directly effect the sensors and can cause sensitivity etc issues. Also measure the proper voltages (I think 5V) at the sensors and their grounds to be good.

The 1st TPS I bought from Napa.
The 2nd one the shop I took it to procured from who knows where.
The 3rd unit also came from Napa.

The 1st time I took the car to the Pontiac Dealer where they ran the diagnostics. I bought the part from Napa and my friend put it in. He works at the dealer.

The 2nd time he couldn't fit me in for a week. So I found a shop to take it to. When the light came back a week later my friend suggested I replace the MAFS.

The 3rd time my car was shooting water from a busted hose. They ran a diagnostic because the light was on when they turned the car on. It came back bad.

It'* throwing that code when they hooked it up. The 2nd and 3rd times were a mere 3 months a part.

I think they are missing something I just don't know what.

Battery is new with no corrosion. I replaced that after owning the car for about 3 months.

I've been really careful about basic maintenance on this car. I put a rod through the engine of my last car.

Ok..the battery is new. Are the cables new or have the boots been removed to ensure no corrosion under the boot? Have the connections for the other end of the cables been checked at their respective connections?

I've been in a position where I had sensors giving me crazy and odd data. In the end..my brand new battery (a Redtop) was clean, as were the connections where I could see them. More investigation provided the culprit inside the cables.

My thoughts on your issue is if the sensor is getting the improper voltage or ground..that maybe that improper amount is causing the sensor to go bad prematurely.

No they haven't.

I'll check that out this weekend.

Are they ACDelco sensors or a NAPA brand? Napa'* stuff is usually pretty good but when it comes to sensors I'd stick with ACDelco. I've had issues with it before on my Lumina.

I am currently getting a TPS error and a MAP error. The car seems to run fine. The only problem is when I put the pedal to the floor, it doesn't seem to drop down a gear and it sometimes gets to around 3000-3200 rpm and then drops back to 2300-2500 rpm. If I drop it down a gear manually it continues to accelerate.