My Engine is Misfiring?

Has it been missing every since the cracked radiator was replaced? or is this a new problem? how long has it been since the radiator replacement and when the misfire started happening? this guide can help us fix it:

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

Please run down this guide and report back.

Ok, the only way to be sure is to have a leak down test or combustion gas test performed to verify whether or not you have a heat gasket issue. That is where you need to start before you waste any money on the car. Does the car have good heat? If so does is suddenly go cold sometimes? Any white smoke? Or antifreeze smell?

Yeah, I would definitely get the leak down/combustion gases test done. If that is negative, which is a good thing then I would have it pressure tested one more time. I hope I have been of some help to you and please let me know how it works out. Have a great day.

You are welcome.

First of all, what are the odds that all those sensors failed at the same time? Nill. Codes never identify bad parts, just failed systems.

The crank sensor is a common failure and there is a tsb on it from nissan. There is an updated flash as well for this issue which would solve most of your problems.
The 171 code is not an o2 sensor, it most likely is a vacuum leak somewhere and can be verified by a smoke test on the intake system.

I would have a shop check this for you as throwing parts at it has not fixed your car. The repairs will probably be narrowed around 1 system.

Roy

After replacement of the sensors, were the trouble codes erased?

Lean running conditions for one bank cna mean a skipped cam timing or clogged fuel rail, vacuum lekages and many more.

Clear the codes and run engine before rechecking the codes again and see which comes up first.

What were the EXACT trouble codes retrieved?

Have a compression test performed to see if they are within specs.

Let start with the P1574 and P0128 since they are the ones that came on first.

DTC P1574: ASCD VEHICLE SPEED SENSOR

Description

ECM receives vehicle speed signals via 2 different lines, and detects vehicle speed for ASCD control. Vehicle speed signals are input from instrument cluster and Transmission Control Module (TCM) separately. Signal from TCM is via CAN communication line.

Possible Causes

Malfunction is detected when ECM detects a difference in values between the 2 vehicle speed signals. Possible causes are:

CAN communication line open or shorted.

Instrument cluster circuit open or shorted.

Defective instrument cluster.

Defective vehicle speed sensor.

Defective TCM.

Defective ECM.

DTC Confirmation Test

Start engine. Ensure TCS is turned off. Select DATA MONITOR mode with scan tool. Drive vehicle at more than 25 MPH. If 1st trip DTC is detected, go to DIAGNOSTIC PROCEDURE. If 1st trip DTC is not detected, system is okay at this time.

Diagnostic Procedure

1. Check for A/T system DTCs. If problem is found, diagnose A/T system. If problem is not found, go to next step.

2. Check VSS, VSS circuit and instrument cluster. Repair as necessary.

DTC P0128: THERMOSTAT FUNCTION

Possible Causes

Malfunction is detected when engine coolant temperature has not risen enough to open thermostat even though engine has run long enough. Possible causes are:

Thermostat stuck open.

Leakage from sealing portion of thermostat.

Defective ECT sensor.

DTC Confirmation Test

1. Replace thermostat with an OEM replacement. Turn ignition on. Select COOLAN TEMP/S in DATA MONITOR mode with scan tool. If COOLAN
TEMP/S is less than 140°F (60°C), go to next step. If COOLAN TEMP/S is not less than 140°F (60°C), allow engine to cool.

2. Drive vehicle at a speed of 50-75 MPH for 10 consecutive minutes. If 1st trip DTC is detected, go to DIAGNOSTIC PROCEDURE. If 1st trip DTC is not detected, system is okay at this time.

Diagnostic Procedure

Remove ECT sensor, and place in heated water. Measure resistance between sensor terminals, with water at specified temperatures.
See ENGINE COOLANT TEMPERATURE SENSOR RESISTANCE table. If resistance is as specified, test is omplete.
If resistance is not as specified, replace ECT sensor.

Please take not that the speed sensor code does not necessarily mean a bad speed sensor. It could be the wirings and other components as stated in the diagnostic information.

The ECT can cause lean running conditions if it is telling the engine conflicting information as compared with others.

Lean running running conditions can be due to vacuum leakages, slipped cam-timng etc. Have you checked those yet?