Catalytic Converter for 96 Limited?

[Wantvegas]

I need to know if my 96 limited has one or two cats. My car has the check light on and when i run the code it says that my emissions are not to operating standards. I think that means that my cat is bad, however the car still passes CA smog! So, I am asking how many Catalytic Converters does my car have, and is there anything else that could give me that code that might be wrong with the car? Thanks!

 

[aldive]

What was the exact code?

 

[Wantvegas]

The code is "P0420" - my book says that the code is " catalyst system efficency below threshold (bank 1)"

So does that mean i do need a new cat? or could it be something else? Thanks!

 

[96eb96]

The code is "P0420" - my book says that the code is " catalyst system efficency below threshold (bank 1)"

So does that mean i do need a new cat? or could it be something else? Thanks!

DO NOT REPLACE THE CAT JUST YET.

You may have failing oxygen sensors that are just above the performance level to give a code. A good scanner can determine that. I would reset the PCM, and see if the code comes back after a drive cycle.

The code is set because of a complex set of measurements and averages over time. It looks at an o2 sensor before and after the cat and sees the change in o2 activity. This is calculated with a weighted moving average over many miles and the light is lit after a certain threshold. The fix below makes the computer less strict as to when the code should be set.

If it still is an issue, and you have a 4.0OHV engine, take it to the dealer and have this addressed:

Article No.
00-26-4 MALFUNCTION INDICATOR LAMP (MIL) - MIL ILLUMINATED - DIAGNOSTIC TROUBLE CODE (DTC) P0420 STORED IN MEMORY - VEHICLES EQUIPPED WITH 4.0L OHV ENGINE ONLY
LAMP - MALFUNCTION INDICATOR LAMP (MIL) ILLUMINATED - DIAGNOSTIC TROUBLE CODE (DTC) P0420 STORED IN MEMORY - VEHICLES EQUIPPED WITH 4.0L OHV ENGINE ONLY

Publication Date: DECEMBER 14, 2000

FORD: 1996 EXPLORER


This article is being republished in its entirety to update the Calibration Information.

ISSUE:
Some vehicles may exhibit a Malfunction Indicator Lamp (MIL) illumination along with a P0420 Diagnostic Trouble Code (DTC) stored in continuous memory with no driveability concerns. This may be caused by the calibration of the Powertrain Control Module (PCM).

ACTION:
If no other failures are observed during normal diagnosis, (physically damaged catalyst, stuck fuel injectors, etc.), reprogram the PCM with the latest level calibration in the application chart. PCM reprogramming should be performed before any emission hardware is replaced. If the vehicle already has the latest calibration, follow normal diagnostic procedures for DTC.

NOTE: PCM REPROGRAMMING SHOULD BE PERFORMED BEFORE ANY EMISSION HARDWARE IS REPLACED.

 

[Wantvegas]

Wow, thank you for the information.

The code does come back after resetting it and a driving it. I have had the some code for as long as i have owned the car (6 months).

Should i replace the O2 sensor? Or should i take it the dealership and have them see if it is a problem with my computer? Thank you for the help!

 

[96eb96]

Wow, thank you for the information.

The code does come back after resetting it and a driving it. I have had the some code for as long as i have owned the car (6 months).

Should i replace the O2 sensor? Or should i take it the dealership and have them see if it is a problem with my computer? Thank you for the help!

If you ONLY get a p0420 code for six months it is very likely your o2 sensors are ok. There are other small issues that could that cause the code, but if the cat looks intact I would go ahead with the computer flash.
Your other option is to get a full diagnostic looking for things like exhaust leaks and the like (check for that too).

If the cat is REALLY shot though, obviously it wont work. What that procedure does is change the passing grade from 65 to 50, so you get the idea. So at least understand the risks.

Good luck