Exhaust System - Sulfur/Rotten Egg Smell
Article No.94-15-19
07/27/94
EXHAUST - SULFUR SMELL - VEHICLES WITH 3.0L OR 4.0L ENGINE
LIGHT TRUCK:
1992-94 AEROSTAR
This TSB is being republished in its entirety to include the latest level parts.
CALIBRATION:
2-56J-R00, 2-56T-R00, 2-58J-R00, 2-58Q-R00, 2-58K-R00, 2-58L-R00, 2-55J-R00, 2-55T-R00, 4-56J-R00, 4-58J-R00, 4-58K-R00, 4-58J-R10, 4-58K-R10
WARNING:
THIS MODIFICATION IS AUTHORIZED ONLY FOR THE LISTED ENGINE. PERFORMING THIS MODIFICATION ON OTHER ENGINE CALIBRATIONS IS UNAUTHORIZED AND COULD CREATE LIABILITY UNDER APPLICABLE FEDERAL OR LOCAL LAWS.
ISSUE:
An objectionable exhaust sulfur or rotten egg smell may be noticed during various driving conditions. This may be caused by the operating strategy of the powertrain control module (PCM), catalyst and/or the canister purge (CANP) solenoid.
ACTION:
Use the following procedure to determine if a new PCM with a revised strategy, a new "double nickel" catalyst is required or the canister purge solenoid needs to be reversed.
The revised operating strategy of the new service PCM's minimizes sulfur odor, improves idle quality, and extends the high cam at cold ambient temperatures below 32~F (0~C) for improved defroster performance on start-up in neutral. The new revised strategy should remove about 95% of the sulfur odor.
A "double nickel" catalyst with a double coating of nickel oxide on the substrate may also be installed on certain 1992/93 vehicles built before 11/5/93 (3.0L) and 10/30/93 (4.0L). The catalyst is most effective in geographic areas with high levels of sulfur in the fuel.
The canister purge solenoids on all 1992/93 3.OL (built before 11/9/93) and 1993 4.OL (built between 10/20/93 and 10/22/93) were installed incorrectly and need to be reversed with the arrow on the valve pointing toward the engine (vacuum source). Incorrect installation of the purge solenoid will purge fuel vapor at idle and aggravate sulfur (H2s) formation.
1. Perform the diagnostic procedure in the 1992-94 Powertrain Control/Emissions Diagnosis Service Manual. Service as required.
2. If the sulfur smell still exists, install a new PCM and reverse the canister purge solenoid, if applicable. Refer to the the following Powertrain Control Module, Catalyst and Purge Solenoid Reference Chart for correct parts usage and required canister purge solenoid reversal action.
3. If the sulfur smell is still objectionable, install a new catalyst, if applicable. Refer to the Powertrain Control Module, Catalyst and Purge Solenoid Reference Chart for correct catalyst usage.
Obtain an Authorized Modifications Decal and list the date, dealer number, and summary of alterations performed. Select a prominent place adjacent to the Vehicle Emission Control Information Decal suitable for installing the Authorized Modifications Decal. Clean the area, install the decal, and cover it with a clear plastic decal shield.
Parts Block
OTHER APPLICABLE ARTICLES: NONE
SUPERSEDES: 93-5-13
WARRANTY STATUS:
Eligible Under The Provisions Of Bumper To Bumper Warranty Coverage
OPERATION DESCRIPTION TIME
941519A Perform EEC-IV Quick Test 0.5 Hr.
And Final Quick Test
941519B Additional Time To Replace 0.2 Hr.
PCM And Reverse Position
Of Canister Purge Solenoid
941519C Additional Time To Replace 1.1 Hrs.
Catalytic Converter
DEALER CODING
BASIC PART NO. CONDITION CODE
DRIVE 08
OASIS CODES: 403000, 623000