check engine light
 

I recently purchased a 2002 mustang gt it has had the catalytic converters removed and replaced with magnaflow exhaust. I did not know this until after i bought it and the service engine soon light came on. I had the computer read and it showed bank 1 sensor 2 o2 sensor was bad. I bought some mil elliminators but the light came back on after about 15 mi of driving. My question is do I need 4 mil elliminators or is ther something else that needs to be done. I placed the 2 that I bought on the rear to sensors then moved one of them to the front sensor when the light came on the first time but it did not help. Any suggestins would be appreciated.

the front 2 sensors are the ones that matter. hook the MIL eliminators to the rear 02 sensors. if your check engin light comes on get the codes and google obd2 codes and look up and see what it says.

to reset the check engine light disconnect the positive battery terminal for 15 minutes. that will reset your computer

when you reset the computer does that remove the tune if you have one? Do you need to flash the computer again?

no the tune will stay with the car. your stock tune is stored in your handheld tuner.

i will put both of the mils back to the rear and reset the computer and see what it does. Thanks for the input if anyone else has some more suggestions feel free thanks again stanger00

Does it matter which batt. cable that is removed for 15 min poss. or neg. just curious to know/

positive

If you have a handheld tuner, you should be able to turn off the rear O2 sensors? No need for MILS

It amazes me that people put MIL's on the front 02's.

The negative terminal should always be disconnected first, not the positive. Disconnecting the positive first can't cause a short. So, to clear the light, disconnect the negative terminal.

i answered someone elses question not the thread starter. i doubt the guy who started this has a tuner.

ok Mr 03gtmustang I have put the mils on the rear o2 sensors reset the computer and once again got the service engine soon light. The code that i get is p0136 you tell me what I should do now.

Some MILs are junk. I tried two different sets with no luck. You may need a chip/tuner to disable the CEL for good.

PO136 This code refers to the second oxygen sensor on Bank 1. The O2 oxygen sensor produces a voltage between .1 mV and .9 mV. The ECM monitors O2 sensor voltage and determines if exhaust is lean or rich. O2 sensor voltage is high when exhaust is rich and low when exhaust is lean. The ECM monitors this voltage and increases or decreases fuel injector pulsewidth according to engine fuel/air ratio. If the ECM detects low HO2Sensor voltage for an extended period, it will set P0136 Conditions required to set: HO2 sensor voltage is low for longer than 2 minutes (minutes depend on model of vehicle. Could be up to 4 minutes)

so bank 1 is on the driver side. O2 sensor 2 is the rear sensor. so switch your MILS around and see if the code changes.

damn...i guess he knows whats up with the problem.

thats just basic troubleshooting and researching skills. i guess the air force taught me something

Something a lot of people dont know how to do.

Yep.... people still dont believe me when I tell them Autozone will read the CEL for free. Dealers charge $100 to hook up to their scanner.

After I drove the car with the mils in the rigth spot I gto the same code from auto zone p0136. So i swapped them around left to the right and right to the left I will see if the service engine light comes on again. If it does I will go back to auto zone and see what code I get then. Thanks stanger00 you have been good help all of this computer crap is all new to me. Ford's have never been at thetop of my list but I really like the mustang aside from the check engine light it runs real strong.

oh hell yeah ohhsoobad2 you would be a fool to take a car to a dealership for a check engine light. just about all of the part stores do it for free.