My car is a aztec pontiac 2001 and the service engine soon light is on. the code is PO420 but i don't know where to start. what i can do? please help me.

Service Engine Soon came back on and the car is again stalling ????? Did you have it checked for DTC'S - diagnostic trouble code's ? Service engine soon light on , codes will be present !

We stopped guessing back in the 90's when car makers started using trouble codes. So should you. Blinking check engine light means you have a serious misfire. So doubtful that it's an electrical problem. Get the codes read and post them. That's the starting point. We stopped guessing back in the 90's when car makers started using trouble codes

This is a serp. belt diagram for an '01 aZTEC 3.4l

My 2002 Aztec radio locked, trac on light, abs, service engine soon light, securiity light and others on, is there a way to unlock the radio and can I replace the BCM and ECM myself? The dealer says over 1100 bucks for just that!

you need to find out what cause this because it sound as if someone was trying to get into your car and the alarm is set give these websites a try www.alldatadiy.com and www.autozone.com if all fails stop in at your local GM dealership and talk with the service manger he or she will be able to help you wish you the best of luck Michigan Man.

the firing order is 4 Cylinder 1-3-4-2 6cylider 1-6-5-4-3-2

You will have to get the codes for both of these modules.Then you can post back and I can help you and explain what they mean.Auto Zone will check the service engine soon light but I don`t know if they can check the theft light.They won`t charge you.

Sounds like you have a bad wheel speed sensor. You need to have it scanned. Since it's been sitting, it might just be a bad connection to one of the speed sensors.

check the bulb in the dash after all its a chev

The PCM is probably storing a B, C, or U code that your code reader doesn't read. Or, it's storing an enhanced P code. If the light goes on, trust me, there's a code stored. You need a professional level scan tool