I have a '98 Mazda B3000, 106K, that does not start easily and has horrible preformance. I have replaced the wires, plugs, #2 O2 sensor in the last 6 months and the fuel pump TWICE in the last two years.

I had a complete diagnostic done yesterday and the mechanic thinks that my CPU is bad. There is no comunication from it to any of the O2 sensors, fuel system, notta. A repacement runs about $850.00, not in my budget, so I was thinking of pulling one from a junkyard and plugging it in? Will this work, are there any after market options where I might be able to increase preformance?

Thanks

 

There will be different calibration codes, but as long you match the engine, trans and gear ratio you should be fine. Another option is to get a junk yard donar and have yours sent off to be rebuilt. A1 cardon will do this and most all retailers carry A1.

 

As far as aftermarket, Unichips may work, but you will spend big money if you opt for thier software. AEM, motec and several others have ECMs available.

 

When you changed those plugs, did you by chance install a new distributor cap? I Had a Mazda 929 running like crap and was told I needed a new computer...turned out to be my new Bosch distributor cap causing the misfires! Replaced it with Japanese brand (Denso I think) , problem solved.

 

It's fuel injected so, no distributer cap. Now I'm getting a code of P1131, a "Manufacter Specific Powertrain trouble Code", which the dealer says has to do with the air fuel mixtuer? Dealer also said there is a TSB that deals with problems similar to what I have been experincing, TSB is about a grounding issue at wiring location X309? Any thoughts on where that might be?
Thanks

 

P1131 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 1

If you haven't replaced the O2s, try that.