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bill, jeep master tech
Category: Jeep
Satisfied Customers: 1628
Experience:  25 years with jeep drivability and electrical expert
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Getting diagnostic codes of PO420 and PO432 on a 2004 TJ

Customer Question

Getting diagnostic codes of PO420 and PO432 on a 2004 TJ 4.0L. It has California emissions. Not sure if the main converter or mini converters or both are the issue?
Submitted: 1 year ago.
Category: Jeep
Expert:  bill replied 1 year ago.

the only cats monitored are the ones directly below the manifold or the "mini" cats those are the MAIN cats the larger one is for NOX, in an OEM replacement case all the cats are replaced as a unit, mini and the larger NOX unit, here is the diag procedure for the codes you have , in 99% of the cases the cats are dead, usually caused by age or poor maintenance, they were designed to last 10 years with proper maintenence

Expert:  bill replied 1 year ago.

following up to see if you still need assistance, if not please remember this site is on the honor system once you are satisfied with the service you rate it, you have already paid to use the site all a rating does is allow the expert to be paid for his time and that comes out of the fee you paid to use the service.

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