# 2007 sentra 3 codes



## davidc304` (Apr 30, 2016)

I have 4 codes, one is displayed two times, 1st and last. P0340, P0037,P0420, P0340, in that order. I put on a new battery and starter and changed the camshaft sensor. It got the car to start but still very sluggish. I checked the wiring harness from the plug all the way back to the ECM. Two wires give me a high reading, one gives a low reading. If i unplug the the wiring harness that contains these wires from the ECM and check the resistance end to end the reading is low, but when i plug it back in, and ground to the negative battery cable, unhooked from the battery of course, I get a high reading again. I also get a high reading on a few of the pins on the inside of the ECM, including the one that the sensor wire traces back to. Can this mean I have an ECM problem? Thanks for any help, if I can be more detailed in order for you to help me by all means just ask. Thanks


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## Car guy (Mar 31, 2016)

What does the downstream heated o2 sensor show (disconnected) on the heater circuit? What V is coming in to that circuit? What are the resistances on all of that sensor's pin combos? See any wiring issue associated with that sensor (damage)? 

When you replaced the CPS, did you do try to a visual on the signal teeth to see if they had build-up/debris on them?

What does the Equivalence Ratio show and what is the LTFTRM (and STFTRM)?

Have you been running rich? For any appreciable period of time?

What were the originating symptoms?

Did you use aftermarket or OEM CPS?


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