My 1997 z28 5.7 engine quit while driving..checked for spark, no spark. Engine codes are po161, po420, po441. any ideas what to check first? thanks.

 

Most likely its the opti. Pull the coil wire out of the opti only and point the end close to the block or throttle body, then have someone turn it over, if you have spark out of the coil wire than it is your opti.

 

Thanks i checked. Theres no spark coming from the coil. guess i gotta check the plugs to the coil for power.

 

Next you can take the ICM/coil off the car and have them tested.

 

P0161 = Faulty heater circuit B2/S2

The passenger side/after cat O2 sensor is not heating up as fast as it should, on cold start. This will not cause your problem. That sensor is just there to verify the cat is there and working.

P0420 = Bank 1 cat converter low oxygen storage.

Indicates the activity on the driver's side/after cat O2 sensor is not what it should be. Could be a faulty cat, could be a faulty O2 sensor, could be faulty wiring. Again, this code will not cause your problems.

Is is possible you've deleted the cats and are running O2 "sims"?

P0441 = EVAP vacuum switch no vacuum when purge commanded

EVAP purge solenoid is not working, stuck shut, plugged with carbon particles. Could also be a vacuum leak on the line from the solenoid to the throttle body. Could even be a loose hose from the solenoid to the vacuum switch, or a faulty vacuum switch. A remote possibility that this could be due to a vacuum leak in the hose that connects to the throttle body, and that might be enough to make is stall..... but it shouldn't stall just because of a leak this size.

No other codes? The Opti will set codes if the optical cam position sensor fails, so that must still be OK. If there is a failure in the high voltage section of the Opti (e.g. = rotor falls off.... not all that unusual) it will not set a code. Check the high voltage wire terminals on the Opti for corrosion. How did you check for spark from the coil? Lack of spark could be the coil, the ICM or lack of signal on the white wire from the PCM to the ICM. But most of those failures will set codes.

 

I used a spark tester, no spark out of the coil. Its getting a good signal from the white wire to the pcm. Also checked the black ground wire. Pink wire has voltage, i used the haynes book to do this. I will have the icm and coil checked tomorrow, coil has .3 ohms. Can these cause my car to die while driving?

Thank you both for the usefull information.

 

Shoebox's writeups are usually better than something like Haynes:

http://shbox.com/1/4th_gen_tech2.html#opti_test

http://shbox.com/1/coil_testing.jpg