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P0139 Car Suddenly Dies

Mazda, 5 Touring 2010
Hey Guys,

Back at it again with my M5. 150K mileage. Wife has been driving and all of sudden the car dies. CEL P0139. I'm assuming its probably not the 02 sensor in this case. What should I do here? I'm fairly savvy. Can someone walk me through how to diagnose this? I am about ready to replace all of the fuel injectors, both 02 sensors, PCV valve and hose, manifold gasket, spark plugs, and motor mounts, just to try and attack this on all fronts. Engine idles rough. Can someone comment on a better diagnostic approach?

2010 Mazda 5 Sport

Above looks like a good page to read.

Basically, test the O2 sensor first. If it passes, it's possibly a leaky/bad injector. That code appears to be indicative of too much fuel in the exhaust on deceleration.

Focus on the fuel system.

Also, beware cheap fuel injectors. They are cheap for a reason. I would buy 1 from Mazda and swap it around to see if I could find the bad injector.

Also...clear the code. Some codes don't come back for a very long time, if at all.
Mazda, 5 Touring 2010
Thank you for the link! It seems like a fuel injector problem then. I’ll start there. Rock auto has some Bosch injectors. Any problem going with those?

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