Technical Service Bulletin (TSB)
Spark Plug Re-Gap to Resolve Misfire Symptoms
REFERENCE:

TSB: 09-016-24
GROUP: 09 - Engine

Date:

July 17, 2024

VEHICLES
AFFECTED:

2023 (LA) Dodge Challenger
This bulletin applies to vehicles equipped with a 6.2L V8
Supercharged HO Engine (Sales Code ESJ) or SRT Demon 170 (Sales
Code AMM).

REVISION: –

MARKET APPLICABILITY:
NA

MEA

SA

IAP

EE

CH

CUSTOMER
SYMPTOM:

Customers must experience a Malfunction Indicator Lamp (MIL) illumination and the vehicle must
exhibit/set one or more of the following Diagnostic Trouble Codes (DTCs):
● P0300 - Multiple Cylinder Misfire.
● P0301 - Cylinder 1 Misfire.
● P0302 - Cylinder 2 Misfire.
● P0303 - Cylinder 3 Misfire.
● P0304 - Cylinder 4 Misfire.
● P0305 - Cylinder 5 Misfire.
● P0306 - Cylinder 6 Misfire.
● P0307 - Cylinder 7 Misfire.
● P0308 - Cylinder 8 Misfire.
● P0420 - Catalyst System Efficiency Below Threshold Bank 1.
● P0430 - Catalyst System Efficiency Below Threshold Bank 2.
The customer may also comment on one or more of the following:
● Excessive vibration.
● Engine runs rough.
● Lack, or loss of power.
● Engine misfire.

CAUSE:

Incorrect spark plug gap

REPAIR SUMMARY:
This bulletin involves checking the spark plug gaps and possibly inspecting/replacing both catalytic converters.

M09 FSAR-TSB-4048

-2-

CLAIMS DATA:

Labor Operation No:
08-17-02-9C

08-17-02-52

Failure Code

Labor Description
Check and or Re-Gap All
Sixteen Spark Plugs
(1 - Semi-Skilled)
Catalytic Converters Replace
(1 - Semi-Skilled)
ZZ

Skill Category
1 - Engine Repair and
Performance

Labor Time
1.7 Hrs.

1 - Engine Repair and
Performance

0.5 Hrs.

Service Action

SPARE PARTS:

Qty
(AR)
1 (AR)
1 (AR)

Part No.
SP639106AB
68623544AA
68623545AA

Description
Spark Plug
Converter, Exhaust
Converter, Exhaust

Notes
Left
Right

DIAGNOSIS:
If the customer describes the symptom/condition listed above, perform the Repair Procedure.
SPECIAL TOOLS/EQUIPMENT:

Description
wiTECH or Equivalent
Spark Plug Gap or Feeler Gauge

Ref. No.
–
NPN

Notes

REPAIR PROCEDURE:
NOTE: This Repair Procedure does not involve the replacement of all sixteen spark plugs, or any
ignition coils. Only replace spark plugs that cannot be gapped properly, have been dropped, or
damaged.
1. Remove the spark plugs. Refer to the detailed service procedures available in DealerCONNECT>08 Electrical / 8I - Ignition Control / Spark Plug / Removal.
2. Using a gap or feeler gauge, measure each spark plug gap.
NOTE: If any plug gap is lower than 0.55 mm (0.022 in.), replace the spark plug (plug gap should
not be opened up again) and start the re-gap procedure. If the plug gap is greater than .75
mm (0.029 in.) then the spark plug needs to be re-gapped per the Repair Procedure.

-3-

M09 FSAR-TSB-4048

3. With the spark plug held in hand and the terminal on the top side and electrode on the bottom side, lightly
tap the electrode against a hard surface to reduce the gap.
CAUTION!!
● If any spark plug gap is lower than what’s specified, replace the plug and start again – do not
adjust. If at any point a spark plug is dropped, a new plug is required.
● Re-gapping should be done very carefully to ensure that the electrodes and the precious metal
tips do not get damaged during the re-gapping procedure.
NOTE: After the first initial tap, if the measurement shows that the gap is not yet within the
required specification, continue tapping and measuring till the specification is reached.
4. Using a gap or feeler gauge, measure each spark plug gap. Each spark plug gap should be between 0.55 0.65 mm (0.022 - 0.025 in.), with 0.60 mm (0.024 in.) being nominal.
NOTE: Each plug that is marked with a blue mark, signifies it was re-gapped correctly and cannot
be re-gapped even if the gap is greater than .75 mm (0.029 in.). If the vehicle returns with
DTCs, or symptom/conditions found in this Service Bulletin, further diagnostics should be
performed. Refer to the detailed service procedures available in DealerCONNECT/Service
Library.
5. Using a blue paint pen, mark each spark plug that was re-gapped Fig. 1.

Fig. 1
Blue Mark On Re-Gapped Spark Plug

6. Install the spark plugs. Refer to the detailed service procedures available in DealerCONNECT>08 Electrical / 8I - Ignition Control / Spark Plug / Installation.
7. Were either DTC P0038 or P0058 set when the vehicle was brought in?
● YES >>> Proceed to Step 8.
● NO >>> Proceed to Step 10.
8. Inspect the catalytic converters. Refer to the detailed service procedures available in DealerCONNECT>11
- Exhaust System / Converter, Catalytic / Inspection.
9. Do the catalytic converters need to be replaced?
● YES >>> Replace both catalytic converters. Refer to the detailed service procedures available in
DealerCONNECT>11 - Exhaust System / Converter, Catalytic / Removal and Installation.
● NO >>> Proceed to Step 10.
10. Clear any DTCs that may have been set.
POLICY:
Reimbursable within the provisions of the warranty.
This bulletin is supplied as technical information only and is not an authorization for repair. No part of this publication may be reproduced, stored in a retrieval system, or
transmitted, in any form or by any means, electronic, mechanical, photocopying, or otherwise, without written permission of FCA US LLC.