Well lately the z hasnt been running up to par! It has been running really, really rich. And it now has developed a miss/cut-out at rpms above 3k. So yesterday i went to advance auto and run a scan tool on it. This is what it returned:

1) Code 11 Malfunction Lamp Indicator Lamp Problem

2) Code 23 Manifold Air Temp (MAT) Sensor Signal Too Low

3) Code 42 Ign System Problem Elec Spark Timing (EST) Is Grounded

4) Code 48 Mass Air Flow (MAF) Circuit Problem

5) Code 64 Right Oxygen Sensor (Bank 1) Lean Exhaust Indication

I can explain the code 48 since i unplugged it once but the others i have no clue. So any help would be greatly appreciated! And oh yea nice forum

 

So no one has any advice or help?

 

just an idea, all sensors get a 5v reference signal from the pcm, check your wiring diagram and make sure you have it, sometimes if you have one bad sensor it will draw all the voltage and causes other sensors to malfuntion. . . did you clear the codes. . . did the car run better. . . did they come back?

 

Not sure what you are after..... do you want some guidelines on fixing each of those codes?

Sometimes you can run into engine or PCM ground problems that set multiple codes. Might be worth fixing the SES light so it works (is it possible someone removed the bulb to cover up the fact that there were codes?). Then clear all the codes and see if they come back.... which ones and in which order.

The other approach would be to put a scanner on there and see what each sensor is reading and why it might be outside of the diagnostic limits, and setting the code.

DTC 23 for the IAT sensor sets when the PCM detects an open circuit, or a very high resistance (inlet air temp very low). You can check the sensor with an ohm meter. I have an online scanner guide that has a table to allow you to check resistance vs. temperature.

http://members.aol.com/InjuneerZZ/ScanMast.htm

How long ago did you unplug the MAF sensor? If it was recent, that explains the code. If it was quite a while ago, the code should have "self cleared" from memory by now.

You need to look at the O2 sensor voltages with a scanner, and check the long term fuel corrections. That will help determine whether the O2 sensor is at fault, or if its something in the engine control system causing it to run lean. You can swap the O2 sensors side to side, and see if the code follows the sensor (faulty sensor) or stays on the same side (wiring or control system problem).

But before digging into the "fixes", I'd do the SES bulb, clear the codes and see which codes come back.

 

Thank u both. I will try these steps and see what happens. I think someone has blacked out the light on the panel but i will check into it. But yea i unplugged the MAF sensor a couple of weeks ago so i can explain that. Ive heard that taking the dash apart is a task. Is this true?

Is there a possibility this miss is due to a bad opti?

 

Why would you need to take the dash apart?

 

To check on the SES light.