I have a Mazda CX-7 that is cutting off while driving. No warning lights such a check engine or battery lights are coming on, car is not making any funny noises, no funny smells or smoke. Car was cutting off randomly but now occurring more frequently. Because no service lights are coming on mechanic is unable to hook it up to diagnostic machine because it will not kick out any codes. This is so scary... Can anyone please offer any help, advice, or suggestion.

 

check the fuel pressure while driving, fuel pump in the gas tank on mine was bad, just wasn't getting any gas.

 

2.3 turbo or 2.5 non-turbo?

You need someone with a decent scan tool that can monitor PID's while driving.

 

more than likely it is water in the fuel. every time the water reaches the fuel injector the engine cuts out because water is not combustible and it leaves no codes. go to your local auto parts store and ask for something that removes water in your gas tank. pour it in and should solve the problem.

 

I just fixed the same problem by replacing the crankshaft position sensor. I've had the exact same problem since I bought mine back in October or '17. The day after I drove it off the lot it stalled on the way to work. It started right back up and the check-engine light did not stay on. The dealer agreed to look at it. They had it for a week...the service manager drove it home each night but it never would stall or show any codes. I drove it for another week before it happened again...just a random stall...no check-engine lights, no codes,(I have access to a code reader) and it would start right back up and run as smooth as ever.

It went about 6 months without a stall or any other problems...then it started again. This time it happened more frequently and sometimes took 2 or 3 tries to start. One day it just wouldn't stay running for more than a few seconds. Though now the check engine light would stay on but for only about 3 starting cycles and then go out. I finally got a code when the light stayed on: P0335 "Crankshaft position sensor A circuit".

It was about $50 and easy to replace. There is good access to it once you remove the right wheel and the plastic cover behind it(4 plastic tabs). Then two 8mm bolts and it's out. Just mark the position & take pics before you remove it. It has slotted holes so must be re-installed in the exact same position.

 

I had the exact same problem on my '08 CX-7. Exact same problem...the day after I drove it off the lot. I then went 6 months...Nov '17 to Apr of this year without an incident. Then it started acting up again...frequently... The check engine light would finally come on for about 3 start cycles (then go away) and I finally got a P0335 code....crankshaft position sensor. By then it was stalling almost every time I drove it.
The day I replaced the sensor I thought I would have to push it in the garage as it took 8 or 10 cranks to start. It started right up afterwards and ran flawlessly for 4 days then one day I went to leave work and it took 3 cranks to start it. But, now it's been over 2 weeks since that episode and it's ran fine. (it hasn't actually stalled, just wouldn't fire up right away that one time).
It was an easy enough job to replace the sensor so hopefully, maybe, I've got it licked.
The mounting holes are slotted so make sure you get the replacement sensor in EXACTLY the same position.

 

 

ive the same problem. Changed fuel pump, hpfp, maf, coil packs, spark plugs, throttle body. Still occurs occasionally when i coast or come to a full stop.

 

Have you tried re-seating the ECM connectors? Check ground?
I've had over 4 months of trouble free driving since I did that. Good luck.

 

I get similar issue, I just finished my service like 10 days ago including recall issue, 2020 mzda3, and the car just died while I'm driving, I bring it back to service and they can't find any error, it's so scary. Cuz normally I often drive on the high way and there are lot of trucks behind. I'm still waiting for their reply.