Please help me with my 1997 Mazda Protege code P0134- PCM

Hi,

I'm a mechanics daughter and a machinist wife. My car will not pass emissions due to a P0134 code. My dad has replace the O2 sensors, idle control sensor, and done some other work. He has determined that it's the engine control unit. He's going out of town and can't help me and my husband, well, it's been stated that it's my car and my problem so I'm doing this myself (so help us all!). I bought a book and have started research, but I have some basic, stupid questions.
1. Is the ECU the same as the powertrain control module? Sounds like the same thing to me, but hey, I'm an optician, I know glasses not cars....
2. Where can I buy a new ECU or PCM unit? I can't get it at my local auto supply store, would I have to order it from the dealer? Or a specialty shop?
3. After market parts, as good as dealer parts?

I have taken apart my console and found the PCM (all by myself, I might add, it was a proud moment!) but an advice or tips would be appreciated. Please help me stick my tongue out at the boys and let me brag about my girl power, that I can do this by myself....and please no laughing!

Thank you!

ECM and PCM are the same. They do not fail that often on mazdas but anything is possible. How does it run? The code definition is for no activity for the O2 Sensor. Do you know what other work he has done to it? Vacuum leaks are common on these and could cause this code also. I would start by looking at the intake duct that goes from the air filter housing to the engine, make sure it is not split will be hard to see you will have to look all around it and possibly remove it to see this could also cause it to stall in drive or reverse and run rough possibly.

Hi Asecmt,

I don't recall what else he has done, I can not say that it runs well, it smokes a lot, the idle will suddenly drop then come back up, I can smell exhaust in the car (and yet I want to keep this car...strange, I know!). I took it to the dealership a year ago and they had my dad do a test on the O2 sensor, and my dad said that the sensor was okay but the ECM was bad. I had 7 error codes on the computer and now I'm down to one. If it is the ECM or PCM, where does one buy such part? If it is a vacuum leak, how could I tell? If I had the car idling, could I see the leak?
Thank you so much for getting back to me!

Well if you smell exhaust in the car the that could cause the code also depending on where the exhaust leak is. The ecm would only come from the dealer BIG$$, or you could possibly find one online. Somtimes you can hear a vacuum depends on how big it is usually you cannot.

Alot of the mazda ecms met an early death because of there location under the cup holders! Soda and electronics don't co exist so well! but again that code very rarely leads to an ecm issue! See my other post about your egr issue and go from there!