2013 mazda cx-5 engine issues

I have changed the following sensors. MAF, Forward O2 sensor. Cleaned the MAP sensor, throttle body had the intake manifold gasket and the PVC valve changed. I have been trying to troubleshoot the STFT and the LTFT. This morning I started the car and the fuel trims were both and zero. After the car warmed up for about 10 minutes the trims went wild. The STFT was positive 20 and the LTFT went to negative 25. After a few minutes they both went positive 20 to 25 and the rpm continued to rise. Any ideas of what this could be? I am running out of ideas. I was getting a misfire and a P0171 lean back 1 code. After cleaning the MAP sensor the misfire code has not come back. The PO171 is there now. I did notice that the scan tool is showing my timing going erratic from single digits to double digits.
GA prior 16 CX5 GT
20 CX5 GT + Prem
Are you using spark plugs with the ion feedback capability? Several others have had wild results with wrong plugs as they are sensors for the engine computer.


San Antonio, Texas
'15 CX-5 Miata AWD
Plugs could be culprit. Wrong plugs, non oem plugs that aren't within spec etc.. If those are original they are 8 years old lol. The manual lists a few items for P0171, some of which you've covered. Fuel injectors (dirty, try a STRONG cleaner such as guaranteed to pass (called G2P) are an easy one to try and clean with an agent.

l Fuel injector malfunction
n Improper operation of fuel injector
n Fuel injector related wiring harness malfunction
l Improper operation of purge control system
n Purge solenoid valve malfunction
n Purge solenoid hoses improper connection
l PCV valve malfunction
l MAF sensor malfunction
l Air cleaner element malfunction
l MAP sensor malfunction
l Air suction in intake air system
l Improper operation of electric variable valve timing control system
n Electric variable valve timing driver malfunction
n Electric variable valve timing motor malfunction
n Electric variable valve timing actuator malfunction
l Improper operation of hydraulic variable valve timing control system
l A/F sensor malfunction
n A/F sensor loose
n Exhaust system leakage
l Poor fuel quality
l PCM malfunction


'17 CX-5 Select
Can you post more complete data after the car is warmed up and attempting to idle?

Abs Throttle Pos
Calc Load
Coolant Temp
MAF in g/s
Timing in degrees
VVT timing (if available)

While I haven't owned the CX-5 long enough to know what the PCM strategy is, here are some quick things to check/try:

Sources of false air:
PCV fresh air hose (plug the nose and the duct hole)
cracked intake duct (examine)
stuck purge valve (plug it off)
Loose oil fill cap
Loose oil dipstick

Misreporting MAF (unplug it and watch fuel trims as engine switches to MAP sensor fuel mapping)
Misreporting MAP (unplug it and watch fuel trims as PCM ignore MAP)
Misreporting intake temp (unplugging MAF will address this)
Misreporting coolant temp (unplug sensor near thermostat). This sensor is more likely to cause negative fuel trims.
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92 MX-3; 18 CX-5
ugh - please don't now change the spark plugs nothing points to ignition.
The lean condition and high fuel trims (eventually a lean code) point to fuel or air problem which is then causing misfire. I'm sorry to be a critical armchair mechanic but only a couple of the repairs attempted make sense given the codes and symptoms. In a way you've addressed some of the culprits of a vacuum leak (or misread air input) by the intake manifold gasket, map sensor and cleaning the MAF. A tool that gives MAF g/s would confirm the MAF is actually working - cleaning it is not a fix, in fact some MAFs cannot really be cleaned. You need to look for air entering the engine that is not getting measured or fuel delivery issue. Low fuel pressure or an intermittent fuel injector could be the cause. Fix the lean code and then replace spark plugs if you want.
92 MX-3; 18 CX-5
Just some thoughts: Vacuum leaks are usually worse when the engine is cold.
Your symptoms seem to be there under idle when warm so primary fuel delivery (pump) seems unlikely. A bad or failing pump would be evident right at cold startup - usually evident by extended cranking. And a bad pump (either tank or high pressure pump) would more likely show up under load - not as evident at idle. So the fact that your issue is at idle and a warm engine makes me guess that a fuel injector is failing when it is warmed up. The best test would be on a warm engine with an oscilloscope measuring current - because the open / close of the injector is so fast. But, you might get lucky measuring resistance at each injector with the engine off after the engine is warmed up and the symptoms are present.