DEC Catalytic Converter ("Manifold Cat") - Rear - separate converters for Cylinders 1-3 (11627503673) and Cylinders 4-6 (11627503675). Fits the following..........

• 323i/ci,Touring (99-00)(E46)
• 328i/ci (99-00)(E46)
• 528i (99-00)(E39)

Fits both standard and automatic transmission models. Quality construction. Not approved for sale in California.

Price includes.........

• Manifold to engine gasket w/Shield - 11621732969 (x1)
• Manifold flange gasket - 18301440183 (x1)
• Exhaust manifold copper plated locknuts - 18301737774 (x2)
• DEC Warranty - 2yrs on the converter, 5 years on the pipes
• Flat rate ground shipping ($10.00 per cat - 48 state only)
• Photo of Rear DEC manifold cat (shows O2 sensor ports)

DEC requires that oxygen sensors be replaced with the converter to ensure warranty protection. Ultimate Garage offers Bosch oxygen sensors for these models at very competitive pricing.

Additional comments - The most common reason for replacing an OBDII converter is a PO420 code ("Catalyst Inefficiency"). This is caused when the rear oxygen sensor(s) detect a fluctuation that is greater than the vehicle's computer allows. The oxygen sensors do not measure Hydrocarbons, Carbon Monoxide, or Nitric Oxide.....they only measure the oxygen retention of the catalyst. If there is any type of air leak, it could trip this code. DEC has also found that using a higher octane fuel than the manufacturer recommends can cause red light problems. It will cause too much carbon to be built up and trip the PO420 code. CARBON BUILD UP is a major problem. Carbon releases oxygen and will give an incorrect oxygen sensor readings causing the air fuel mixture to be incorrect. This also causes more carbon to build up because of the incorrect fuel mixture. Carbon needs to be cleaned out to maintain proper air fuel mixtures!